1) People receive spam from Digital Ocean. They run their own mail servers, but can't handle spam, and this is Digital Ocean's problem. (I stopped running my own mail server because of spam, but I don't blame DO for that.)
2) Fraudsters are prevented from signing up. I am sure VPS providers have a ton of people that don't pay for their service, so blocking them at signup time is probably mandatory. From some of the complaints, it sounds like people have their payment declined, DO contacts them, they still don't have money, and then DO cuts them off. That seems totally reasonable to me. I don't think a VPS provider could make money without some sort of strict account termination policy and anti-fraud analysis before signup. It's bad customer service, but if you can't pay your bill, you're a burden, not a customer. Them's the breaks.