Why do you play 2. Bc4 against the Sicilian?

it a bad move because white fails to appreciate how easy they can penalize the misplaced bishop. after 2...e6, the bishop looks silly on the c4 square, black can also harass said bishop with the natural a6-b5. in fact, the queenside thrust is often the better way to go as after d5, exd5 exd5, white can play bb5+ which is sometimes not so terrible. Quite often black "bluffs" that he will play d5 via e6, but play for a6-b5 and only if white plays a4, then d5! and now bb5+ is not an option.

2.bc4 is often played by beginners that are used mostly to king pawn games and cant tell why unlike agaisnt 1.e5  bishop on c4 is a mediocre square for their bishop agaisnt the sicilian.

but like only 2000 + rated players would understand that it isn't just beginners

Actually, no you haven't.  Where do you see an extra tempo?  Do you even know what an extra tempo is?

In your Nimzo game, it is White to move.  In your Boulder game, it is BLACK to move.  It is merely a REVERSED position, NOT REVERSED WITH AN EXTRA TEMPO!

There is no extra tempo for White.  So now, White is simply playing Black.  Even in the best of defenses, which the Nimzo-Indian would be one of those against 1.d4, Black still only scores in the upper 40s in percentage because Black is still at a slight disadvantage.

So now in your line, in 6 moves, White has an ever So slight DISADVANTAGE!

A DISADVANTAGE in only 6 moves!  FOR WHITE!

You've proven nothing except that those that claim 2.Bc4 is DUBIOUS AT BEST are right!!!

I actually don't think Bc4 is as bad as some say.

Here's a sample line where black goes for what you described: e6 and b5 plans:

Not so bad for white. It looks like a fighting game.

Yes, Bc4 is not the optimal second move. If anything, it gives black the easier opening moves, and leaves white going through some contortions, to justify his bishop placement.

But it's still playable, especially if you're a player who doesn't concern yourself too much with what's "best", and would like to play a game now and then that strays off the beaten path.

@24
"Where do you see an extra tempo?"
++ Look at the 2 diagrams. In the Nimzovich Indian Defence line white has played Be2, in the transposition from the Bowdler Attack of the Sicilian Defence black has not yet played ...Be7. So white plays the Nimzovich Indian Defence Reversed with one tempo more.

@22

"play for a6-b5 and only if white plays a4, then d5! "
++ Yes, ...a6 prevents white from transposing to a Nimzovich Indian Defence Reversed with an extra tempo. However, white does not need to play a4.
1 e4 c5 2 Bc4 e6 3 Nc3 a6 4 d3 b5 5 Bb3 Bb7 6 Nf3 is still OK: a lead in development.

Neither of your lines are forced, and you are going based on an INFERIOR line, so congrats, you got a useless Bishop move in on an inferior line.

1.d4 Nf6 2.c4 e6 3.Nc3 Bb4 4.e3, 4...O-O, 4...c5, AND 4...b6 are all superior to 4...Nc6.

4...Nc6 is MILDLY more sound against 4.Qc2, which is in essence a transposition from the Mexican Defense (aka Two Knights Tango), which is yet another inferior defense.

You still have not convinced anybody with any chess skill that 2.Bc4 is anything better than dubious at best!  About all you have going for you is that there is no documented refutation.

I thought all black has to do to refute white's opening was to equalize. Isn't the point of white's opening to gain an advantage? It can be a tiny advantage but if he fails to gain even a tiny advantage, shouldn't his opening be considered refuted?

Fischer liked bc4 and there are some players that still use it.

That's what I have been thinking too. 

It is true that White being White can start the game in a silly way e.g. 1. Nh3, 1. a3 etc. and still be equal. But by doing so White gives up the opening advantage. Now, the question I wanted to have answered regarding the Bowdler Attack (1. e4 c5 2. Bc4) is why would White want to do that? 

Yes, I get it - Bowdler Attack is not losing nor does it give Black an edge. But it gives Black equality. Now there are more main line ways of playing the Sicilian for White which give White small advantage. So, why play the Bowdler instead? Why??

@34

"Bowdler Attack is not losing nor does it give Black an edge. But it gives Black equality."
++ It gives white a playable position, still a lead in development, not trading a central pawn d4 for a wing pawn c5.

"Now there are more main line ways of playing the Sicilian for White which give White small advantage."
++ No, after 27 moves of Najdorf or Sveshnikov main line black has equality just the same.

"So, why play the Bowdler instead?" ++ Because it is just as good and avoids piles of theory.

I'm not sure if that is really true. I mean  players still win games at the top level in the ICCF and engine aid is legal there. I don't really trust an engine's evaluation of an opening that much anyway. The other thing is even if what you say is true, there is a big difference to me in allowing black to equalize on move 2 ,as some have suggested the bowdler allows, compared to move 27. Maybe black can get complete equality if he plays well but one should at least make him work for it, shouldn't he?

@37

"players still win games at the top level in the ICCF and engine aid is legal there."
++ Players make human errors and thus lose games.
https://www.iccf.com/event?id=85042

'I don't really trust an engine's evaluation of an opening that much anyway."
++ 'If you let the engine run long enough then it is a draw' - Carlsen

"there is a big difference to me in allowing black to equalize on move 2, compared to move 27."
++ Indeed, after move 2 the opponent has 25 moves to make an error before move 27.

"black can get complete equality if he plays well but one should at least make him work for it"
++ After 2 Bc4 black has to work for it, in a main line black has 27 moves of theory as help.

There is some point in what you are saying here. shirov once said if you need to win a chess game it is best to start the game as early as possible. He has also said that when he has white, he feels a responsibility to try to play for an opening advantage. My feeling is that 2. Bc4 accomplishes the former but not the latter. The trick is to find a balance between these two ideas.

@39

"play for an opening advantage"
++ There is no line that accomplishes that.
Mainline Najdorf or Sveshnikov after 27 moves of theory ends in equality just the same.

I would still argue that Black has to work much harder to get this equality in Najdorf or Sveshnikov. By playing 2. Bc4 White hands over the equality to Black on a silver platter. Sure, you can do that - you can play an equal position from as early as move 2. But WHY? Why not at least try to play for an edge?

There is a reason why White players prefer e.g. Ruy Lopez over Four Knights or Nc3 French over the Exchange variation. So surely, other ways of handling the Sicilian as White should be preferable to 2. Bc4. 

Am I missing something?

stop worrying about (from mesmerize to memorize ?) openings and just play. ur like me...ur too louzy to get into titled player theory.

How does your reply contribute to the discussion?

Why there always have to be people who answer the question "How/why do I do X?" with "You should not do X!" ?

Openings are something that I am interested in. Some people study butterflies, others collect vinyl records. I study openings. Why should you be concerned with it?