But not all of them are like that, right? Just like any population or group.... a handful can be inadequate or bad. But not all are like that.
I suspect the selling of snake oil attracts a certain sort of person... mostly.
They're either technically illiterate, and so can be conned by even better salesmen, or know the deal and look at the bottom line - their pocket.
I have a friend who once sold 'better' electricity deals to people by knocking on their doors. Mostly old people. He knew he was often selling them a poorer deal than the one they already had, but made a fat commission.
Eventually his conscience couldn't stand it, and he got out.
Many don't.
Allan