Why is Ruy Lopez even a thing?

It might help to point out that pawn moves don't count as development. In other words, sure white's bishop has to "run away" but black isn't gaining any time because it's only pawn moves.

Also worth pointing out is that pawn moves are always double edged. It's not the case that a pawn is necessarily better on a further rank. They weaken the squares and diagonals they leave behind, and in general the closer they get to the other side the more vulnerable they become.

The good point is pawn moves gain territory / cramp the opponent.

The Ruy is one tough opening to face as Black, though I do face it without the Berlin nonsense. 

As White, If someone plays 3... Nf6 against me, I play Nc3 and go to the Spanish 4 Knights. See how they like that! 

More recently, many Morphy Defense (3...a6) lines with c3 & d3 have been revived. 

I have played the Italian for decades and always wished that I studied the Ruy when I was a youngster. I didn't, because I didn't appreciate the intricate nature of the long-term pressure exerted on Black's King-side. When you start to understand why this works, you become a better player in general.

Yeah, black has many options against the Ruy but it can cost them if they mix ideas too freely.  In my example white’s e pawn is defended and the knight on f6 blocks black from making moves like Qg4. 

The Italian bishop can be harassed too though.  On b3 the Spanish bishop exerts pressure on the same  diagonal without being as exposed.  Even when it drops back again to c2, it still does a lot of work in the center and aims at the black king side.

Many times white will go after the black pawns, but the Ruy is more flexible than that.  There are plenty of lines where black controls the queen side and white goes in for a king side attack.  The Ruy is a full board opening, white can look at the king side, queen side, or center for play.

It’s a huge opening to take in so you may want to play some fun secondary lines to get started.  When I started as white I played an early Qe2. Other people seem to prefer the d3 lines or even the C.A.R.L.  

the great thing about Ruy is that it's sophisticated and difficult to play on BOTH sides, so most games mainly come down to who is the better player (and better prepared)!

Because on the 4th move White can exchange on c6 for better or for worse.

Years ago I bought a book called 'SPANISH WITHOUT a6' when I realized how far theory went. Today I cope with it as black with the classical 3 ... Bc5. Most players at my level are suspicious of this move and castle allowing me to play 4 ... Nge7 and settle down with a position that over the years has met with reasonable success that I have become comfortable with. I do realize that this variation is not as dynamic as others but it does away with loads of theory.

That's the eternal trade off: simplify theory memorization vs. play something more likely to get a decent result. 

When I played the Ruy Lopez, my response to the Classical was this:

Dang it didn't show

I had that book Spanish Without ...a6 years ago. 

It took me years to figure out why a6 was a good idea.

@DrSpudnik Yes, a6 is a utility move especially useful in defusing the Grand Prix Attack in the Sicilian Defence. We have to learn a lot of theory with ... a6 which is why I have avoided it.  White has played 12 different 4th moves with me in 634 games, the most popular being 0-0, c3, Bxc6, Nc3 and d3 which is considered the strongest. I have always played the Italian as white but have to face the Spanish as black. I have had the Italian as black 874 times.

I grew up playing the Italian but wish I had learned the Spanish instead. I'm slowly drifting in that direction as I head toward my dotage.

There's a lot (potentially) to learn.  Quite overwhelming for a casual player....  Interesting read all, thanks for the comments!

After just 3.Qf6 the Ruy is destroyed

Show us some games to prove your point.

This is just another troll turd of a post. 

Side note: Moving a piece multiple times is only against opening principles if the opponent makes development progress meanwhile. In this case, this is not clear at all, because a6/b5 gains space, but also creates potential targets and doesn't develop anything.

Um... no