It means exactly what it means, the staff unfortunately does not have an infinite pool of patience to deal with some posts that are neither positive or proactive, instead some posts are quite detrimental to the overall topic and progression of the thread.

When a thread gets to this point, it'll be closed.

You're making a very generalized question out a very specific matter, so I'm just going to answer your questions:

We have all the will power to address proactive feedback.

I'm not sure what you mean by "support a 'select few', suggestions are about the suggestions being made, not the person making them.

If you mean do we only consider suggestions from a 'select few' ? The answer is clearly no. We consider every single suggestion, usually the discussion on a suggestion is done internally.