You can drop this complaint on Blizzards doorstep.
They gave everyone a "free" 90 just for buying the expansion. The content from 90 to 100 is so easy most classes can solo it at level. And the barriers to enter heroics are little more than a minor annoyance. I mean they practically give you your first epic and the Proving Grounds are just a DPS race (at least for DPS they are).
I had a level 100 Hunter, today, insisting that his pet "didn't have a growl" because it wasn't on his pet's action bar. He argued with the group for half the dungeon. We finally booted him.