"If you are what you HAVE and you lose what you have, what then are you? But if you are what you ARE and you lose what you have, no man controls your destiny".
And people who only login for raids do? Or how about the ones that spam the same dungeons over and over and over.. wow they play so much more of the game. Blizzard doesn't even need to create a world for these people, instances would suffice.
So why should someone who does more content be left out?
Show me someone who only does LFR do heroic raiding. I'd absolutely LOVE to laugh my ass off. There's a reason LFR exists, and It's because people are too fucking stupid.
And lol @ spamming dungeons over and over. Again, show me someone who only does heroic dungeons attempt a Mythic 10 or 15. Guaranteed they'd wipe the group XD