I can think of at least one other prominent example where another territory did just that and it is seen as totally illegitimate by basically everyone in the west. Which is it?

separatist regions of Ukraine? Haiti? Northern Ireland? there's so many good options to choose from

The NATO intervention in Yugoslavia was hardly to prevent a genocide NATO values human life, including muslim people. I won't deny conservatives in western countries tend to be anti-muslim. I'm going to evaluate Yugoslavia on it's own context and not based on wars in the Middle East.

One of the most interesting facets of the NATO air campaign is how they managed to demolish all the state owned factories and infrastructure, but leave the ones owned by westerners.

This sounds like a conspiracy theory to me.

There’s also another issue with what NATO did to Serbia - Kosovo voted to unilaterally secede. I can think of at least one other prominent example where another territory did just that and it is seen as totally illegitimate by basically everyone in the west. Which is it?

Oh, if you mean the Donbas region, those elections were a sham. It's best not to believe Russian propaganda.

The US was their first backers, getting 9/11’d was just blowback for shitty decisions made decades ago, and murdering a bunch of Afghanis and Iraqis was hardly defensive. We totally had troops guarding poppy fields and oil derricks for like 2 decades after as a part of that “defensive” operation.

We were attacked by state sponsored terror. The war in Afghanistan was defensive. Iraq not so much, like there were never weapons of mass destruction.