People are going to vote for what they enjoyed (although that term perhaps doesn't fit games with tragic stories). Someone who hates contraption or slider puzzles probably are going to vote something more inventory based as their favourite. That's okay with me. We're here because of an interest in the adventure genre, so I think a lot of AGS-ers would recognize a well designed puzzle when they see one, too. For me personally, it's other categories that give me pain. Like Best Programming...I'm clueless enough about the subject that a lot of stuff people pull off, leaves me baffled. Then the authors themselves claim to have made it with spaghetti code. This is one award I feel should be there, but which is very difficult to judge. I believe a lot of us feel that way about music, too, as the majority probably are writers and/or artists, not musicians.
Another democratic problem, sort of, is that almost noone will have played all the games released last year. Especially the longer, commercial releases may have fewer players, I fear, although I have no numbers to back that up with.