I think the major point was that, yes an experience developer can make a good accurate quote, but it needs the requirements to be nailed down and in fine detail

I think the major point was that, yes an experience developer can make a good accurate quote, but it needs the requirements to be nailed down and in fine detail before that quote really means anything. Being that most clients probably don't know what they want until they see it, accurate requirements are hard to find. More common these days are some user stories and lots of rapid iterations until the client is happy I guess.