Let me see if I understand the dilemma here. You supported the dev with a monthly subscription fee for presumably a good long while, during which time he clearly misled his supporters about the timetable of the releases of updates for his game (we're now about 14 months past the release of the last update to Summertime Saga), and you as a result stopped paying him for the service he wasn't providing.
Why aren't you allowed to complain? Maybe nobody cares what you think, and maybe it doesn't even make you feel better about the money you wasted, but you have paid for your right to complain and more. If you like, compare it to the cost of Starfield. Starfield costs $70. Anybody who paid for Starfield and didn't like it has the right to complain. Well, if you paid at least $70 for Summertime Saga over the time you supported its Patreon, I think you have every fucking right to ream DC, metaphorically speaking, for his shitty business practices. I think you have the right to complain if you paid any amount for what is now clearly a scam, too, but I think $70 is a very meaningful threshold for the point where you have bought the right to complain if you're worried you're a freeloader, as it is the going price for a new and (presumably) complete AAA video game right now.
The standard that only people who are currently paying a $5/$10 monthly subscription for an indie porn game get to complain (especially since those people are least likely to complain because then they look dumb) sucks. Complain! Complain away! You have my blessing and encouragement, and anyone who tells you otherwise doesn't have an opinion worth listening to.
