It's not childish. That's the main problem with open source as a whole: devs expect somebody else to maintain projects indefinitely long, for free. This is what's unsustainable.
As discussed in https://news.ycombinator.com/item?id=20174418, with comments from devs represented in that "Software below poverty line" article, the interpretation from the article is seriously flawed.
See "Software below poverty line": https://staltz.com/software-below-the-poverty-line.html