I think you misunderstood him. You may have heard him say
"...they never work right"
What he really said was
I'm not gonna bother with your damn fixie conversion cuz it's not gonna make the shop a lot of money and I couldn't be bothered with all the questions you're gonna ask me cuz I don't want to look like an idiot since I won't know the answers
Do the conversion yourself and search on hear for answers to any questions that come up. We'll be glad to help.