As someone who lost probably 10 batches last year, amen to that.
From personal experience though I think a large part of it is environmental.
I brewed for years with dirty fermenter taps and a mediocre sanitisation regime without an issue. Then I moved and got a problem, and was buying new fermenters, disassembling everything and boiling, cleaning everything, sanitising, like mad, and still not able to shake the problem.
Then I moved where I brew, and the problem went away, even with equipment that had had infected wort in it, and going back to 'a quick spray with a hose and some starsan'.
It's unfortunately not as simple as severity/paranoia level of cleanliness = chance of infection