> Why do you then tell others how to live their lives?
In all reasonably-free societies, the default stance is "Mind your damn business, and everyone else will mind theirs.". Deviations from that default veer into "telling other people how to live their lives" territory. Sometimes it's right and proper to actively interfere in the lives of others. It is occasionally even extremely important to do this. But -the majority of the time- the folks doing this are nothing more than busybodies sticking their noses in other people's business.
You might think that US-based businesses should not be permitted to accept payments tendered by the two major credit and debit card processors for the sale of more-extreme pornographic content. I think it's none of those processors' business what legal goods consenting adults purchase using their systems.
Given Visa and MasterCard's enormous size, I think it's absolutely essential that they not be permitted to refuse any legal purchase for any reason other than credible suspicion of fraud. You may feel differently. You're totally entitled to that opinion.