I just help out by validating issues in Gemini, this is my main adopted role as part of the QA team. I also do point out things out from time to time which are mainly Gemini related (I pester if you like). I am not core, there's a subtle difference here, I don't play a part in taking core decisions. Quite frankly I'm quite happy about this situation at the moment.
Yes there is a QA team, and they do a lot of background work that you don't see or probably just take for granted, you just see me more nowadays because I'm the guy validating the issues in Gemini before they get looked at. I know the QA team lead does a heck of a lot of background tasks that you guys don't see. Please don't ask me to comment further as really it's not in my place to put words into other peoples mouths or make comments on people's behalf, they would not like that.
This is also open source software. You should understand that all the teams work on different time zones and locations. Some people go on holiday, some people are busy working on something else. Almost all of us are not paid to do this (yes we are all quite mad). So sometimes you just have to wait for things to come out in the wash. You should also realise that by contributing you are also in effect part of the team (this is key, do you have anything to contribute?), it's that it is just a different dynamic then say, Microsoft.
On the whole it works out quite well, but by no means perfect... If the core team spent all their time in the forums then no work would get done. If they didn’t spend any time in the forums you would wonder what is going on. There is a balance. In fact right now I realise I have been posting too much recently, and intend to cut this right down myself!