To continue that last thought, I think that another problem is that consumers in this market generally don't possess enough automotive knowledge to understand what is going on with their cars. The ones that do probably do most of their own repairs, the ones that don't have to go to shops. When someone doesn't understand why something is broken, and they have to pay a fair sum of money to fix that item, it can become hard to generate an atmosphere of trust. Especially if a technician doesn't have the time to explain things with his customers - then there's the double problem of not only does the customer not understand why his bill was so much, but there's also probably not a very good business to customer relationship either.
Partly due to the increasing complexity of today's cars, but also to the fact that skills that aren't being passed on from generation to generation, I think that home auto repair is becoming a bit of a dying art. In a way, I think that people who contribute to this site are performing a bit of a public service.