Engh... I think the issue is that a lot of open source maintainers ARE doing that work but are doing it FOR FREE and it is burning them out, because they AREN'T doing the thing you are saying where they just write the parts that excite them: they are also triaging bugs and incorporating feedback and are having to constantly answer people demanding timelines... if they weren't doing all of that stuff we honestly wouldn't talk about the issue so much as we wouldn't be caught in a lurch when they stop providing us all that free value!