This is the flip side of "they're a certified airline, so their training must be legit, right?", with the weird world view that simply the act of checking a box on a form means that everything is good to go.
These days, everything last thing needs to be checked off like it's a Part 25 transport. That alternator belt that cost you $120? Yea, that's just a $10 reboxed belt from PepBoys that someone said "yup, looks good" and stamped a PN on it, but their parts process from 1963 allows for it, so it's still good to go. People forget that when brands C/B/P/M started, the certification process was not quite so rigid, and there was more room for individual effort. PMAs could be easier, but weren't really necessary when the manufactueres were pumping out 3000 airframes a year. STCs could be often received with the local FSDOs/GADOs (remember those?) and field approvals were common.
Our whole GA ecosystem came out of that environment, but is now clamped down. Even your garden variety Cessna or Beechcraft needs to go to a specialty shop. Commodity parts are in short supply. When commodity parts like oil filters are on 6 month backorder, the system is on the verge of collapsing.
I was seriously thinking of upgrading my airplane, but seeing what was going on, I'm relieved to be out of the game until things shake out. The next big drama is the 100LL issue.