Considering they have a quarter billion active users, a "horror story" once or twice a month is an amazingly, amazingly low dissatisfaction rate. I don't think PayPal is actually causing that many merchants much trouble. It just appears that way, because:
* At most merchant services providers, underwriting happens up front: you have to describe your business, what you're selling, expected volume, etc. on an application, and go back and forth with the bank, before you are allowed to accept credit cards. PayPal lets you start immediately, and only gets the information from you once you've started transacting some meaningful volume. So the risk problems are weeded out with other processors right at the start, where with PayPal it can come up suddenly.
* These people have never even thought about underwriting and risk assessment. They treat PayPal as if it's a consumer service, when PayPal has to treat it seriously -- they're essentially making a rolling loan in the amount of 6 months of your transaction volume -- because if you disappear, they're on the hook for the chargebacks for all your past payments. People do stuff no other processor would let them do -- like taking massive donations with no prior approval, selling pre-orders to software that hasn't been written yet -- and PayPal isn't OK with it either once they find out.
* PayPal merchants are disproportionately more often individuals than actual businesses compared to what other processors see... because it's so easy to open an account, and everyone that's used eBay already has one.
* Because the merchants are individuals, and have no experience with underwriting at other processors, and have previously used accounts suddenly limited or frozen, they're confused and surprised. Add to that customer service that won't really tell you much once an account's been closed, and you end up with a couple really angry people a month: cue blog post about how PayPal is evil and if only it were a bank, they couldn't do this.
Even given that, I think PayPal has done a poor customer service job.
They long ago could have introduced some sort of premier business account that drags serious merchants through a proper vetting process.
Then they could have made the "we're scared of you" experience for non-premier users much less confusing. They clearly have a lot of internal structure and rules. They want to keep some of that hidden, to minimize fraud hackery. But they could expose the broad strokes to users, make clear what state they're in, and offer them the opportunity to upgrade to properly vetted merchant accounts at any time. People aren't upset about the restrictions; it's their arbitrary, opaque nature that makes them seem so unfair.
I think the real problem here is that PayPal is owned by EBay. I hear EBay is getting better, but the place used to be a nightmare to work at, and one glance at their website tells you how thoroughly they're focusing on exploiting their existing model at the expense of trying anything new. With that kind of ownership, I figure anybody with a desire for innovation long ago left PayPal.
* At most merchant services providers, underwriting happens up front: you have to describe your business, what you're selling, expected volume, etc. on an application, and go back and forth with the bank, before you are allowed to accept credit cards. PayPal lets you start immediately, and only gets the information from you once you've started transacting some meaningful volume. So the risk problems are weeded out with other processors right at the start, where with PayPal it can come up suddenly.
* These people have never even thought about underwriting and risk assessment. They treat PayPal as if it's a consumer service, when PayPal has to treat it seriously -- they're essentially making a rolling loan in the amount of 6 months of your transaction volume -- because if you disappear, they're on the hook for the chargebacks for all your past payments. People do stuff no other processor would let them do -- like taking massive donations with no prior approval, selling pre-orders to software that hasn't been written yet -- and PayPal isn't OK with it either once they find out.
* PayPal merchants are disproportionately more often individuals than actual businesses compared to what other processors see... because it's so easy to open an account, and everyone that's used eBay already has one.
* Because the merchants are individuals, and have no experience with underwriting at other processors, and have previously used accounts suddenly limited or frozen, they're confused and surprised. Add to that customer service that won't really tell you much once an account's been closed, and you end up with a couple really angry people a month: cue blog post about how PayPal is evil and if only it were a bank, they couldn't do this.