Lack of reputation might be a factor in why software outsourcing sucks, but the dentist analogy doesn't work.
How does the average person find a dentist? They ask their neighbor or co-worker, who says, "Well, I go to Joe on Maple Street, and he's OK." Seriously, how many dentists does your neighbor actually know? It's probably exactly 1. How many dentists has your neighbor gone to in his entire lifetime? Probably 2 or 3. He has no basis for making comparisons.
I trust neighbors and co-workers to give me movie and restaurant recommendations because the average person has experienced hundreds or thousands of those.
PS: Here's how I find a dentist or doctor when I move to a new city: I do a Google search for ones nearby, look up their credentials, then choose one who went to a recognized university and whose degree is not too recent (inexperienced) and not a terribly long time ago (outdated knowledge, retirement age). This can't be any worse than selecting the 1 guy that your neighbor knows.