I've been using PayPal for like 15 years and I've never had a problem with it. "Until you do" is not an acceptable answer to my question. Things work until they don't, that's not a reason not to use them.
It's not even that bad for users. Paypal sucks for people on the merchant side of the transaction. People who actually accumulate money in accounts are those that always complain. Merchants feel like they have to stick with it just to open up more payment options to their customers though. Now paypal even keeps all fees no matter if a customer returned an item. So if you are selling say cameras for $1000.If someone returns the camera. Paypal keeps about $30 - actually you are out $30 for every return.