On the subject of scammy devs, I think a note should be made of Patreon.
Like gym membership for a couch potato, Patreon suscription prosper on the hope that you will suscribe to a very small contribution per month and mostly forget about it. At any point, the act of canceling your subscription is more a hassle than loosing a few buck every month. You forget, you go on, you falsy rationalize than you COULD have usage of the suscription again. Most ONG don't take punctual donation anymore, they rather ask you for a small montly automated donation.
Some people are meticulous and accountable enough to look at their ledger often and terminate any no longer wanted suscription. Most people aren't.
Call it scammy, call it behavioral scheme, that's how Patreon is doing business. Are the devs accomplice of such business ? Are we willingly allowing that ? Well, it's the easiest way around. And we like easy.