Yeah, he will be severely limiting himself if he aborts all games that are not of a certain type of opening. By limiting himself, I mean that he is limiting the level of skill that he can reach in chess.
What are the rules on Aborting games?

Check out this #chess game: Bacia420 vs lilmorphy - https://www.chess.com/live/game/65445211059
I was playing a game and was winning. Then the opponent somehow aborted the game when moves had already been played. The game never went in to my game history as it was counted as an aborted game. How is this possible for someone to do this?
Are you sure they did it? The servers may have gone down for scheduled maintenance or otherwise rebooted - all games are lost when that happens, IIRC.
Thanks for the reply. I don't remember the guy's name. Anyways, I've noticed this is a thing at level 800-1150. Above that, I haven't encountered this yet (but obviously a small number of games). I now also think, that this shouldn't matter too much (low priority issue I would say).