Simbrodev and breeding season both kind of allowed themselves to milk on the way out - the income started a steep decline and they just kind of let it trickle out without contributing. I think the later kind of ponied up and closed it when they realized they couldn't go forward anymore (drama/long story).
I honestly don't know what system could work in this scenario - I want to reward indie artists, but I also want to keep them producing. Personally I think a better way to handle this type of thing would to not allow reoccurring donations, forcing people to keep intentionally donating (I know this is very impractical). I also know that it would impact Patreon/etc's money flow so that's never going to happen. On the other hands the kickstarter model hasn't proven any more effective (22cans/Godus comes to mind).
As the codebase expands, updating it gets more tedious - and after a while enthusiasm wanes. I doubt Dark cookie is out there twirling his mustach, laughing at the patriouns without returning any code - but he has had kids, the code is getting bigger, and I am sure his motiviation to timely deliver new code has waned sigificantly. TBH if I were him, and had read 1/10th of the comments on this thread whining about it, I would feel unappreciated, and my motivation would stink too - regardless of the income.
