I think that forums do provide useful input, but it has to be filtered. If people do have opinions about certain items it means that they can be changed for the next major release, but maybe not at all in the way that what's said on the forum.
I think if an indie dev does not read his forums and personally respond to posts, he won't be an indie developer for long.
Yes, the dev should not personally moderate the forums, but they have to understand that they are going to have a small player base to start with because they are most likely a niche game and in order to continue sales it is imperative they have some response to concerns and quests by the community. If you alienate the people who have actually bought your product with a wall of silence, then they will think "this douche doesn't care that I spent $20 on his game... f' him!"
Now there are some people you aren't going to please at all no matter what you say and most of the time you are going to reply "feature was WAD" was as designed and "patch is forthcoming and will be ready when it is ready" but it shows that you are trying and that is good enough for some.
Also, as a small time developer you aren't going to have paid QA staff and 9 times out of 10, your player base is going to be the ones reporting bugs through the forums.
A really good (no longer small) company is Paradox interactive where it is not uncommon for a developer to respond to a post complaining about a game saying "That shouldn't be happening. Could you send me a save game so I can take a look for myself?"
And as far as niche goes... Paradox is very niche and they are going strong after 10 years because they are active in their forums and people really respect them for it.