Knowing where the money comes from is fundamental is so many aspect of our society.
Getting a loan from a bank will require you to disclose some information about your money getting activities. Why? First to make sure nothing illegal is going on, and second to make sure you will be able to pay back the loan.
Running your political campaign will require you to disclose how it's financed. Again why? Because people realized long ago that you don't bite the hand that is feeding you or something. Meaning you should expect a strong bias by that politician for their backers.
And so why care about a public figure getting money from the Koch Industries? Because it adds a crucial information on how to process the opinions coming out of that public figure.
Yes it's possible that the source of money doesn't affect anything, but it's also highly possible that it does and many times it does, so why not care about it?
> not just the mouthpiece of some think tank ad campaign.
If you get some benefit from using them as a dev, it's either incidental or part of a larger plan to lure you into their corporate "ecosystem" (think: why is React so much more dominant than Vue or Svelte?)
This is just a straw man. Who cares who pays him? I could say the same thing for:
Typescript. It's literally bankrolled by Microsoft, insert quip that says Typescript devs can't have good intentions here
Tensorflow. It's literally bankrolled by Google, insert quip that says tensorflow devs can't have good intentions here
React. It's literally bankrolled by Facebook/Meta, insert quip that says React Framework devs can't have good intentions here
Etc.