Stripe is a nightmare. They are the only payment method to have a payed blog on Substack. They closed my account because I talked about open source software. Said it was against their terms. I disputed. I wasn't soliciting. No reply. Just quietly ran out the dispute period time and then closed it.
I assume GP meant "malicious activity" - as in, a successful product launch looks a lot like a scammer from the perspective of an automated system running for the payment processor.
It's bizarre how this article goes from trashing on Stripe into an advertisement for the product they're reporting on. I'd say something like "I expect professional integrity from the authors at iMore!" but I don't know who I'd be trying to fool.