I use Paypal all the time on websites because of the "devil you know" philosophy. I know them. They are pretty evil, but at least I know to what extent they are evil. I'd like to sell stuff through them but well they are just too tough to deal with to make it worthwhile.
They have interfered with commerce on almost every level. Their API is pretty antiquated and full of obfuscated settings. By now I should be able to sign up to a website, give them my info, upload a virtual product, and collect money from whoever buys it.
I should NOT have to pay if someone tries to fuck them over. That's their problem. But Paypal totally ruins businesses that get targeted by chargeback scammers, to the extent that they SHOULD BE INVESTIGATED FOR FRAUD... because it's pretty likely that at least some employees in Paypal are fraudsters. This recent leak could have been an inside job.
If you ever need to dispute something with them just toss a coin. You'll never know if you'll win unless you have an agreement with them that is tested and works. But even then... who knows?
Don't try to do anything nice for anyone like collect charitable funds because you'll have a bad time.