I’m pretty sure they don’t deny transactions. They just threaten to pull out. If they clearly state that they don’t have customers with explicit content I think that’s fine, but I assume they went full bully instead.

These companies tend to have rules about what types of transactions they want to be associated with and only have deals with companies that adher to that. When I was working in Klarna they were very clear that they did not associate with porn, sex, weapons etc. Of course they also own the bank Sofort that handles shady customers.

The problem here is that these providers are so big that it’d be a major blow for Steam to lose them and hence they can be bullied into submission.