Great topic. So here my answers, many will duplicate those posted by others:
1. Ranking/ELO system for all coop games, forced on game design. There is no real reason to not have one. There are games on BGA that have it, or something very close to it.
2. Game testing on Alpha phase. Its absurd now. You have BGA reviewers that played few time and voted to move game that was unplayable at all, with 2 major crashes while was still in alpha.
You have 1000+ people in game test group and maybe 50 are actually doing something, and rest are complaining that you post your observations and looking for players on that group chat. What for they joined there in first place?
Test by playing game won't find many bugs anyway. Even perceptive and dedicated person can't really test things without proper tools to change game states. So you end with game that is years after fully published and still have basic rules not fully implemented, which as I recall is a reason to NOT move game to BETA.
3. Guru system. For years now there is "more option will be added soon" message and nothing is done. BGA created that feature for something and then stopped. So for now guru's are only for arena settings vote. Not even real vote because 1 option is always a current arena settings, and there is not even vote reset between vote 1 and vote 2 stages - absurd.
4. No real handle of "kingmaking" and similar problems. A lot of excuses here instead.
Clearly is a problem for community, based on many topics, and only what you can do is give RT. To what point? If a many people give same player public RT with "kingmaking" reason, will that alert a mod to do something? Even that is unknown.
5. Bugs not being addressed with idiotic "by vote order". Number of votes is good way to evaluate proposition, but not bug. For example: table crashed bugs are critical, but affects only few people at that table, so who more you expect to vote on them?
After recent "paintjobs updates" I had few crashed tables. Those were fixed but my report is still not updated, so I assume fix was done accidentally, not based on my report.
6. Replays are just terrible. Hard enough to use it when you want just learn or watch a game. Much harder when you need to look it to give as many information as is possible for bug report, or to make tutorial from it. You don't need to load whole game history and play it step by step so even fast getting to move you look for takes minutes when it should take seconds. And if you write wrong move number you CAN'T GO BACK only forward - absurd.
History loading is also problem in normal play. You don't need load whole game history to make your TB move. Juts recent history. That will cut loading time to 5% in some long games
7. If you want volunteers to do stuff for your page, give them tools. Now those tools are clumsy and make working MUCH harder, so less people want to do it.
8. Much better response to what players want, not what staff (including volunteers), publisher game author, wants but what players of game wants.
9. General revision and change of basically all BGA policies. And communication with players, which is now not really existing.
See, we found common ground. Key phrase being, "provided I'm not flooding the system with pointless reports."