I come from a background of starting out working for main dealer (16 years ago now) and now own an independant specialits, I know many main dealer techs that for many marques that are friends, many of them are very very skilled but treat it as a 'job' rather than a passion and work for business owners that are simply driven by profit and they really dont care about doing things properly, much the same as a main dealer I worked for.
I also know and am friends with indy owners, and they really care about everything they do and doing it well.
After seeing the mess that dealers leave cars in before being sent to us (toyota sent us a corrola with the exhaust unbolted and held up with cable ties, the numerous vag cars with incorrecty fitted timing belts, oil changes with incorrect oil ) I cant see why people pay extra for dealer work.