Literally 100% of payment processors heavily "regulate" what their customers sell/do and who is profitable to do business with and what clients are profitable to associate with.
For example, if an industry has a humongous chargeback and fraud rate, then they become unprofitable and get dropped. This is why American Express stopped allowing porn (there was news articles about it at the time and they went on record saying massive amounts of chargebacks and fraud from porn sites were solely the reasons). American Express and Visa also don't allow you to use you to use your credit card to pay your mortgage (Mastercard does). I don't know the reasons why, but I'm sure it's not arbitrary.
They also have to conform to laws and regulations. This is an offshore company, PayPal is based in the United States. I don't know if its legal to sell this sort of spamware-as-a-service in the United States, but I think there might be AT LEAST copyright issues content harvesting that they appear to be doing (based on other comments).
It's not just that: these are businesses, not the government. A lot of free-speech advocates and libertarian thinkers seem to think somehow that private businesses somehow have a responsibility to uphold free speech, and they simply don't. It's the government that can't restrict you from free speech (in the USA); but companies don't have to put up with it on their property or when using their service.
Many people believe that businesses and corporations have a responsibility to uphold and respect free speech as a societal virtue moreso than as a constitutional right. This isn't a crazy position given the power many companies wield over the workings of society.
Social pressure on businesses has always been a big part of capitalist societies and this pressure comes in many forms. Ultimately societies of people are far more than a sum of their economic system. Economic systems shouldn't be what defines the morality of the people in society, that comes through community, culture, media, etc in addition to the judicial systems and governments (which all capitalist economies operate within).
Who are these "many people"? Libertarians? They're a tiny, tiny minority.
There's a simple saying about free speech: I'll respect your right to free speech, but I'm not going to provide a podium for you. If you want to speak freely, you can go to any street corner and do so, but don't expect my company to provide a platform for you if I don't agree with your views.
For example, if an industry has a humongous chargeback and fraud rate, then they become unprofitable and get dropped. This is why American Express stopped allowing porn (there was news articles about it at the time and they went on record saying massive amounts of chargebacks and fraud from porn sites were solely the reasons). American Express and Visa also don't allow you to use you to use your credit card to pay your mortgage (Mastercard does). I don't know the reasons why, but I'm sure it's not arbitrary.
They also have to conform to laws and regulations. This is an offshore company, PayPal is based in the United States. I don't know if its legal to sell this sort of spamware-as-a-service in the United States, but I think there might be AT LEAST copyright issues content harvesting that they appear to be doing (based on other comments).
These are businesses, not charities.