Why do people say "I want it done fast"?

Fast is modifying 'done' which is the past tense of a verb. Verbs are modified by adverbs - which end with 'ly'. They should say "I want it done quickly".

A similar mistake arises about cars (and other the things). It may be a fast car, but you drive it quickly - you do not drive it fast.

I discussed this with a professor of computing who said "It doesn't matter - it's common usage". Common or not, it is wrong. Yes, or no?

Does anyone care anymore? Does anyone know anymore?