Perhaps a slightly different take on this ...
Before I joined PF, while still just a guest, I thought that 'Theory Development' was a forum for folk who were developing theories to get an early critique of them, say a month or two before submitting their first paper for peer review. I felt it would also be a good place for an independent researcher to float some 'extension ideas', based on new work they were doing, after having laid the foundation with a PhD thesis, a one page letter paper, etc. And indeed, here at PF we have at least one such researcher, and previously had maybe one or two others.
What I wasn't at all prepared for was the disconnect between what I consider to be the basics in science and just about every post I read in TD! (I should say that there were some exceptions - perhaps only a half dozen, out of hundreds or maybe even thousands). This brought me down to earth with a thud; if TD were to work as I had, in my naivety, imagined it should, then how to remove the nonsense from the 'real contents'?
Then there's the Pareto principle (a.k.a. the '80/20 rule') - those who have volunteered to help develop and maintain PF should be spending ~80% of the effort on PF's main goals; instead, I got the impression that several mentors and admins were spending ~80% of their time managing TD! I think the new policy will allow a better alignment of effort with goals; I'm all for it.