To me, the main issue is the fact that BGA implemented a concept of "reputation", with a moral sense in it (by naming it "karma"), that is at like 95% attached at playing on time (and the "5" other % are hidden from players: we know exactly how players lose karma when their opponent hit on red, but we do not know how you lose points otherwise: what is too many red thumbs? how is it calculated? how much points do you lose?).
It feels like BGA basically tells us: we do not really care how friendly you are, if you salute your opponent, if you try to help, etc. What really matters is if you are able to respect time limits. And if you do not,
for whatever reason, then you are someone
bad. We will even use a moral* concept to make you understand it perfectly, and openly show on your profile how good or bad you are.
* : To be fair, the concept of karma is more impersonal and less religious and manicheist than that of sin and the like in christian spirituality for instance, but it is still moral.
And it is quite frustrating.
This might be personal, but to me, the biggest issue isn't that you lose elo and reputation (although I don't understand why you should lose extra elo instead of just the equivalent of a simple loss), it's the fact that it's kinda morally framed like this, even just subtly.
You can win a little bit of respect by doing translations and the like, but this will not jump to the eyes as immediately (it's impossible to know unless you go to the profile of the player and read that part). This will just earn you a small discount on your subscription. It will be called "gift-points", and if you use them they will disappear. In a sense, it feels like it is a matter of paying by a form of work, very laboriously, and you will be rewarded for participating quantitatively and making arbitrary changes. What matters is not exactly that you spend time on the translations, only that you manage to get your translation to be the last one.
And since the gift-points vanish after use, the only real data appearing to show directly your level of contributions is the number of translations made (even if you did poor translations in a niche language en masse without getting caught, just to earn your subscription).
BGA has implemented a system for rewarding players for their behaviour, but in the end, unless they do things outrageous (like kingmaking) and are caught and reported, they are good players if they play on time regardless of all the rest (maybe they are douche who never say gg or anything nice, they sneak in technically-not-insults coldheart remarks, they hit red as soon as possible when they lose, etc.), and bad sheep otherwise (regardless of everything else, even if they contributed a lot to translations, offered enlightful remarks in the forums, helped numerous players to understand games, etc.). It feels like wasted potential.
I don't say it is easy to find alternatives, but in any case, the system feels frustrating. To this specific regard.