It's not a bad idea. It's a realistic idea. If people want to live on a pink puffy cloud, then they should expect to fall on something hard when reality eventually comes knocking. Healers and tanks have insta-ques. If you want to play with insta ques, you need do make a tank or healer.
I'm sure the game is prohibitive for a lot of very casual gamers. For that I am glad they made a game for people who actually want to play more old school kinda of MMORPG where you cant solo everything. Heaven forbid you try one of the zillion single player mmo out there.