scotch is pretty underrated
Scotch Game questions
Kasparov indeed used to play it, think even in match against Short several times.
scotch if too much straightforward, even a small advantages which white may get out from this opening cannot compensate the facts; it leaves you no choice to deviate much and in this way for black is easy to prepare. It reminds me on Berlin var, even worse.
I used to play it few times against low rated opponents, but I was not satisfied at all, Ruy Lopez provides much more choices and plans.
Personally I think non professionals can get away with anything reasonable as white. When it comes to the highest level of chess though, it is safe to assume that Kasparov knows a thing or 2 about a thing or 2.
My point about the candidates was that even though many players play the Italian (and not just to get around the Berlin), when it came to a tournament that was THAT important, the Ruy Lopez was used far more than the Italian. I don't think that the Italian is bad at all, but I also don't think I know as much about the game as GK.