I still have tonnes of .rar. Exclusively for legacy reasons (you can google why .rar exists), sure i could spend the time extracting everything, or continue using Kodi which is my current solution.

I don't think the license is the issue, Kodi has solved it with a external dep if i'm not mistaken. The reason is more related to your last sentence. They don't get it, and thus doesn't want to spend time on solving it. Which is their prerogative of course, but it still annoys _me_ :)