There are certainly some negative people on the site, but the moderator team do a good job of making sure any criticism is genuine and not a personal attack.
It started off as a side-project for fun, now has grown so large it's my primary income. Unfortunately it hasn't left me with enough spare time to enjoy LEGO much though.
My kids enjoyed LEGO Masters (Australia), and it certainly seemed to bring some new people to the site.
There have been several attempts that I know of. But they all tend to have a low number of categories they sort into - tens vs the thousands of actual categories that exist.
I have tried it myself and it simply needs more input data (ie photos). However, that is something I might follow up on later as I can fairly easily get more data just by asking my community :)
The sorting can be quite relaxing for some people (ie me). Kind of like a background task you can perform while watching a movie and calm your mind of things.
https://rebrickable.com - A LEGO database that shows you which sets you can build from your existing collection, also includes thousands of fan-submitted designs.