You're jumping to conclusions when you assume everyone wants everything. Not everyone does. You also seem to confuse need with want with the way you used them together in that sentence. We all have things we want and would like to see added/changed but that doesn't mean those things are needed.

It's a general forum for feedback. Players are free to agree or disagree based on what they personally want. It's not working against each other, it's expressing a different opinion about what they personally feel would make for a better game experience.

Developers still get additional feedback from other sources as well since only small percentage of players use the official forums. Safe to say that just because one person replies in the forums that they don't feel something is necessary isn't going to translate into the developers thinking that no players want it.

I agree about hijacking threads to discuss other things. If someone wants to bring up a different subject, they should go to a thread that already exists for that subject or start one if they can't find an existing thread.