I seriously doubt the community values artist integrity less than "hundreds of existing discussions"

No, it does not, which is why I applied it only as justification not to enforce the per-day rule as it should've been before; violations of those rules are no longer harming anyone in the way the rule was designed to prevent.

If I dig up an old comic with the word "fuck" in it that was never removed, would you remove it now that curse words are allowed?

As I said, I don't enforce rules ex post facto. There was no such rule before, but let's say it existed. I would not, and you have to know that's meaningfully different. Punishing someone ex post facto is very different from granting leniency ex post facto. "I've decided this is bad, so I'm going to actively punish it retroactively" is extremely different from "I've decided this is fine, so I'm no longer going to prosecute it." You definitely understand that "I'm criminalizing weed, so you who smoked it a year ago are off to jail" and "I'm decriminalizing weed, so I'm going to drop existing charges" are completely different regardless of your stance on weed (although I know roughly what both of ours are).

And, of course, that's not even the case here; no actual rule (unlike the "fuck" one) was broken at the time it was posted, so I'm not setting a precedent that we can change the rules at any time and apply them retroactively.

The point of having rules around content isn't to punish users who break the rules. It's to shape this place into the community we want it to be.

Actually, the rules are around to protect the users and what they contribute here – so they can safely post and comment knowing what's in-bounds and have grounds to object if they think they were unfairly punished. If I wanted to "shape this place into the community we want it to be", I could just go around removing whatever because I think it beautifies the community. I don't apply ex post facto punishments, and I'm likely to grant leniency ex post facto; these two are entirely consistent with each other.

I can probably link at least one thread where I went off on Beep if you think any of this is meant to stick up for them specifically. I requested to moderate expressly because Beep was ruining the community, and I was even surprised to see them granted amnesty and tried to see a silver lining.

You're welcome to think I'm a misguided idealist, but my hobbies are creating copyleft software, copyleft prose, copyleft media, and copyleft data requiring attribution, so if you think any of this is because I'd wish to wipe every one of Beep's de-attributed posts any less than you, you're understandably but sorely mistaken. I feel Beep spat in my face personally along with the rest of my community's. I just don't have a proper justification within the rules – and that includes the per-day limit applied as a backdoor in a way that's not in the spirit of that rule.

That said, I will show no leniency to intentionally de-attributed posts in the future, and I'll be making sure all have proper credit.