Unfortunately some seem adamant that their MMORPG experience isn't complete unless they can spam <SPACEBAR> over and over.

that was not even true.... even in WoW. Go actually play the game and count them out. In 2 years I saw at most 3-5. and it was few and far apart.

really the jump spammer was a myth. And who cares what other ppl do.
It in reality NOT breaking your immersion. Just your realism No one can break your immersion. Unless your mom calls you down so you eat your cheesy poofs and pot pie. Immersion is intercting with in an enviroment other then your own. Like reading a book and becoming that character in your imgagination or how those places look.

Immersion in video games are how much you can interect with the enviroment. So jumping since it increases enviromently interaction ADDS immersion.