If people want to do them for others, then they should be encouraged to do so. Very few people can be bothered with doing so though, as it's time and effort that makes a job about 10x longer than it otherwise would be and that makes it a PITA. Everyone is as bad as everyone else in that respect, myself included.
I agree with the idea, but there is absolutely nothing that can be done about it unless you offer people an incentive. On a free forum, that's spectacularly hard to do unless you can get folks to put their hands in their wallets. Hell, I'd put together a guide for something if people were willing to pay me for my time, but otherwise it's unlikely that I would ever bother. Not a helpful attitude, I know, but at least it's honest and one I would guess that a lot of people would subscribe to.
There are some notable exceptions of people on here who are far more helpful than I, and there are some folks who help guiding in people in person as opposed to writing proper guides, which is equally commendable.