Paypal declared the war to NSFW stuff since almost 10 years ago, so much effort for something as simple as some stupid doodles... Funnily or Sadly enough (however you want to see it) I pretty sure that they standards are similiar to Devian Art
Photos of naked womans = "Oh!!! So artistic, keep the good work, make sure to starting selling your stuff, feel free to use all our tools to increase your income"
Pictures of naked cartoon = "Thats immoral you psycho!!!! BAN!!!"
Cryptos will become the only way sooner or later...