Is this really a tactic?

I'm in agreement with uri65.  I don't see this as any different than a mate-in-1 and there are thousands of those in tactic books.  Personally, I could count the number of times I've missed a hanging piece or hung a piece on one hand, if one hand had a few thousand fingers.  The piece needs to be captured and there is a 99% chance it's a tactic even if it's simple.  For a similar tactical motif in my own games I might have to look as far back as yesterday. 

Chess is 99% tactics.  -  Rudolph Teichmann

The tactician must know what to do whenever something needs doing;the strategist must know what to do when nothing needs doing.  -  Savielly Tartakower

Uri, if that's how you prefer to see it then I guess that's fine. :)

You can lead a horse to water but you cannot make them drink .  

1.e4 e5 2.Bc4

I think 2.Bc4 is a tactic because you have to calculate to see if Bc4 is a legal move, and then you have to check to see if it's safe.  Also, you see these types of moves in tactical books all the time (i.e. moving pieces).

^
Is what you sound like.

Or in this case, you can lead your horse to a bishop, but you can't make him take.

I'd be interested to know what the pass/fail rate is on this tactic.  

2.Bc4 is not a tactic - there is nothing forcing about it and no short-term gain. But how do we know that there it is no tactics? I can see three possibilities: 1. One knows the position precisely - in your example it is a theoretical opening line. 2. One recognizes that position is quiet. But this requires some experience. 3. One checks for possible tactics, calculates lines etc. Weaker players are rather limited to option 3. For example I am quite week in the opening theory and already as early as move 4-5 I have to calculate and double-check for tactics.

Few quotes:

"In general I consider that in chess everything rests on tactics. If one thinks of strategy as a block of marble, then tactics are the chisel with which a master operates, in creating works of chess art."  -  Tigran Petrosian

"Half the variations which are calculated in a tournament game turn out to be completely superfluous. Unfortunately, no one knows in advance which half”" - Jan Timman

"If the student forces himself to examine all the moves that smite, however absurd they look at first glance, he is on the way to becoming a master of tactics."  -  Cecil Purdy

"Good players develop a tactical instinct, a sense of what is possible or likely and what is not worth calculating."  -  Samuel Reshevsky