No, it won't be the 'same percentage' at all. Let's not be dishonest about this. Yes, there's players at the moment who don't pay attention to their rotation or mechanics. Nobody is contesting that - the concern is that inevitably players skipping large portions of content will result in more players having a poor understanding of the game. Say what you will about the levelling process but it does, at least, encourage players to learn something during their journey. Buying their way into the endgame scene doesn't.
This exact same situation has already played out within WoW anyway. Thus why a lot of us feel so strongly about it. We've seen the effects, the slippery slope it leads to and the apathy of 'it doesn't affect me'.