Indy shops can be just as guilty, I wouldn't lump all dealers together.
Personal changes as well, I used to take my 944 to the dealer, but its a different set of people there, especially corporate side, and they tend to create more trouble than they cause.
An indy shop I used to take my 944 changed owners/managers, never again will go under that ownership. I was trouble free before.
I am somewhat suspicious after taking my 944 to a shop, to find the bolt that holds the clutch fork pivot in place loose. Since I didn't inspect beforehand, I can't say for sure, but that is tightened down with a separate nut to help lock it in place and should not be loose letting the clutch fork pivot rod fall out!
You shouldn't really separate dealer shops from indies. TBH, you should always stand in the bay door and watch if you want good results.