To take the metaphor from a different user on this topic:
"Its completely ok to not hold the door open for someone, but its extremely impolite to drop them into their face."
The author created a project and advertised it to people, if they don't want to maintain it anymore, sure, no problem.
But deleting it to spite others is considered a d* move.
I work in open source as well at both day job and for "fun" but I fix the issue that I want and if people want something from me as author of whatever, there is going to be a money talk.