Paypal hates everyone, not just developers.
Also, much of the complaining about Paypal seems to be in the form "I violated Paypal's ToS, and then they closed my account." Well, maybe you should read all those legal documents before entering into a business agreement?
The payment processing part seems to be great until it goes wrong but when it does they have the minimal resource possible devoted to dealing with it.
I've also had a lot of clients that used paypal to sell stuff. Paypal hated them too.