I think that you may be onto something there. I have noted that when I meet (many) ex-Amazon employees, a lot of them (especially on the business side) are not nice people to work with (backstabbing, destructive political games etc).

It's come to a point where I kinda assume that they are likely to screw me/other people if I don't know otherwise.

(Obviously this is a generalisation, I'm sure there are loads of really nice people at Amazon).