I blame reverb as much as people using reverb
My personal fave was a guy who came over to test the Fryette PS2 I was selling. He tried it for two hours, sent an offer via reverb which I accepted, took it home and filed a claim a week later, stating the unit was noisy and making high pitch noise. When I got it back, I noticed via the vents that something was off. Not sure why he started changing the power tubes. It should have two 6L6, had one 6L6, and one EL34.
I got ballistic on his ass, claim rejected but it cost me shipping, time, and tech expertise