Yeah, agree that a nasty dunk is a big motivator for everyone, or damn scary for the opposition, but I've probably seen more 3 point daggers that I've seen dunks change games.
I would say more people can dunk now than not dunk, but if a player is constantly dunking it, then it can be easier to defend and deny (double team, force them out of the paint etc etc)in the block then some trigger happy freak that is lighting it up from the carpark. In a team concept the freak constantly draining the three is much more dangerous than then bloke chucking down nasty dunks.
That ok, I'm speaking PG language....aka head up arse/world revolves around the PG syndrome lol. It's something they teach us at PG primary school.