Yes time is a factor, but so is countless hours of practice and theorycrafting, PTR testing, in short, dedication and efforts lead to a high level of play if you have the potential for it, and thats far from something that anyone can do no matter how much time they have.
To the OP : No. People are and should be free to play however they want.
I'm nowhere close to play at their level nor would i even want to and i didn't really care for the world first race since Firelands but i still find hilarious how much people try to hate on those guilds and downplay what they do. Guess jealousy and bitterness are common human traits.