We already have a bad reputation within the DK's community. Everytime I pug with a DK, they are either so full of themselves, or just plain bad. If people want to use a boosted char on a DK, then it doesn't help.
The learning curve is shorter when you play a DK than any other char (except DH) when you don't use a boost.
It gets boring having to tell them how to play their class or ask them to be humble. They're easily the 2nd (or maybe third) most hated class in WoW for a reason.