The status of the Evans suddenly changed when Kasparov dusted it off and used it as a surprise weapon against his top 10 rivals. Suddenly it was back in fashion, at least for a while. But once the novelty wore off, it again declined in popularity, possibly condemned by the cold hard logic of the modern analysis engine.
To be fair, the other reason it tends not to get played is that 1.e4 e5 2.Nf3 Nc6 3.Bc4 isn't always met by 3. ... Bc5. 3. ... Nf6 is a more fighting response, so much so that 3.d4 is now often the mainline if 3.Bb5 is not played (again Kasparov had a big hand in this).
But just today I reached a position where I could play an Evan's, albeit via 2.Bc4. Initially I was surprised I even got to this position, and despite not being a serious Evan's player myself, the temptation to play 4.b4 was just to great. Fortunately I remembered enough of the general ideas behind the opening (sac all your pawns!) to play the obvious moves, and with a little help from my opponent scored a win in a manner that shows how dangerous it can really be as an opening.
Press,Shaun - Unger,David [C52]
Street Chess, 05.09.2015