I prefer not to enter a conversation about plugin pricing. I’ve already been involved in too many and I only know one thing is certain: no one is right and all of them are 
Coming back to your suggestion. I would be worried if a plugin I use had 20 installs. But with more than 30K (apps and not users) a fork with a hot-fix would probably be out in less than Bubble’s average turnaround for any other issue.
I proposed some weeks ago to start a community that would handle these kind of plugins to be supported by the community instead of single users.
It has stalled a bit since due to other commitments but I will come back to this shortly.