Going paid is their fair right, there's nothing wrong with that. On the other hand, forking the project and immediately shitting on the years of work and community building of the upstream with toxic blog posts seems very childish.
I'd rather support a closed source project than a community that actively promotes toxic behaviour.
What? Have you ever heard of soy, beans, lentils, chickpeas or the huge variety of seeds? You don't need meat to get your protein, as many eastern folks have proofed over many many years.
I'm not looking gor a dev that knows it all by heart. I'm looking for a dev who knows how to get information about stuff he doesn't know.
A take home interview therefore gives me a much better picture of the real-life skill level of a candidate compared to a very stressful situation like a real-time whiteboard interview.
Also: Give your candidate a real problem to solve and pay them for their time!
Just read up on the emissions of animal agriculture and transportation and be enlightened my friend. You will see their emissions are not that different in size.