I've been banned from Paypal, I assume because my account has been hacked twice (they never gave a concrete reason) among 100s of legitimate transactions over many years. What is frustrating is "this limitation cannot be appealed" - it seems to me that the true scammers wouldn't even try appealing, so I think they are firing me rather than accusing me of acting maliciously.

Fair enough - they are a business who wants to maximize profit, and I was being a 'bad' customer. But I think this is short-sighted; they are a social payment network and every lost customer is millions of potential payment links destroyed. I've already made a few people use competing services to send me money. Paypal has consistently thrown out the opportunity to be a de facto online payment standard in exchange for a higher margin.