Saying it’s possible some regionals are intentionally failing people does not mean it’s never the pilots fault for a failure. No one is saying that.

No one will ever have a perfect checkride. If an examiner wants, I guarantee you they could dig until they find something to fail you on. Depending on how much leeway you have with the checkride is set up, you can easily create a Kobayashi Maru scenario. Kill an engine 49 miles from a mountain airport hard IFR with a short contaminated runway and only a localizer approach and 51 miles from a clear international airport. They go to the mountain, ding them for not exercising their command authority and going to the better runways. They go to the big airport? Ding them for bypassing a suitable airport.

Luckily no one I’ve ever run into has this attitude, but when one person has been doing checkrides for a decade and has 20,000 hours in the airplane, and the other is a new hire, there is going to be cracks in their armor even if the new hire studied above and beyond what is expected.