Puritan is defined as finding porn etc distasteful, so it really is. one who practices or preaches a more rigorous or professedly purer moral code than that which prevails https://www.merriam-webster.com/dictionary/puritan

It’s the objection itself not the reason for it that’s important. In other words objecting to porn on artistic grounds is still puritan.

Reason is very obviously hardcoded into the definition with "moral" word.

Ergo,

>objecting to porn on artistic grounds is still puritan.

is not true

Valuing “good” art is a moral stance. It’s a judgment of what human behavior is good or bad.

It's moral stance if you define good as moral. In other words, your reasoning is a circular reference, and not very useful

Different definitions of the word good here. Someone who thinks “good” art should should be destroyed is making a moral judgement in the same way someone who thinks it should be preserved.

It’s defining something as positive or negative which makes this a moral judgement not the specific value assigned.

I use positive/negative here because someone may believe there’s an incorrect solution to a math problem without judging such errors in terms of morality.

I don’t think that word means what you think it means in the context it’s being used. In this case a moral judgment simply means with respect to ethics. One could morally judge something to be good, bad, or neutral.