I think their point is that there are a lot of people for whom $300 is a great payment - essentially, defending the maintainers for offering what the parent seems to be implying is too little.

Personally, I'm a senior dev making more than triple what I did when I started my career, and if it were five minutes of work (or even ten, or an hour) I'd be extremely happy with $300.

I included people that are doing FOSS work in there. I also have found very few software engineering tasks that are 5 minutes of work. I am not looking down on 3rd world developers, it is just a simple fact that in most of the western world, doing a few days of work for $300 is not going to equate with getting a job as a software developer. Assuming it takes a week to tackle one of these bounties, 40 hours of work, That is a bit above minimum wage in the US. Even 20 hours is only $15 an hour. I don't think this will inspire professional developers in expensive nations to try and make a serious effort, for just the money for just a simple fact that it doesn't pay enough. But there are many classes of developers that this is good money. I am defending this bounty.

Ukraine may be poor, but devs there aren't even getting out of bed for $300