Why not make feedback forms/polls once in a while and ask everyone for their opinion (via forum, ingame, or even social media)?
I’m a designer myself, and I understand that hoping to get feedback passively is next to impossible.
We approach them and ask them actively, directing the feedback into what we want to know. By doing this, it’s much easier to sort out which problems most people are having (and sort out which ones are nonsense). There we have our priorities straight.
The technology to automatically categorize forms is out there, don’t only rely on a suggestion dump like this in the forums.
The clock is ticking IMC.
p.s.
Sometimes those nonsense reveals the true subconscious feeling of people and it may be much more valuable than a logical reasoning made by amateurs.
One more thing, sheer quantity can make subjectivity into objectivity.