Best short explanation I've seen of the situation...... With the game currently there is no reason for the person worried about a couple minutes of completion time to play, or accept a wizard into their group, over a Sorcy if given the choice. Sure you will run into a few quests out there that a particular Sorcy may not have the spell selection for the fastest possible completion. But those are few and far between.
I'll still play my 18wiz/2rog though... Because I simply don't care about a couple minutes, as long as it's not an hour.... And I'd say at least 90% as a best guess of the DDO population feels the same way. Play what you have fun playing, what you find effective and don't worry about what the desperate to be noticed say.