They are targeting incest/rape games. I wouldn't call that 'LGBTQ' like some people seem to imply. If Itch and Steam don't want to police their store fronts _before_ the law gets involved, then I am not surprised that other businesses such as payment providers will choose not to work with them.
Visa and MasterCard are in the business of making money, they're not doing this for fun.
Visa and MasterCard are in the business of making money, they're not doing this for fun.