I'm sure I'm not the only one who regrets Ben Crowell's decision to become unactive on PSE. He stated the reason for his departure in this post addressing the ratio of professional physicist users to beginners, pop-sci philosophers and other 'lower level users'. A big part of that reason seems to have been that he finds himself "spending my time on the site in unenjoyable activities like arguing with angry and belligerent beginners about friction and Newton's third law".
While I can sympathize, I feel like this is something everyone determines for themselves. You don't have to argue about these topics with these users. Then again, it is alarming that these discussions seem to have become more frequent, also in my experience (which, granted, is not as long-term as Ben Crowell's).
Now, an idea popped up in my head which might help restore the balance somewhat or at least halt the dilution of the uranium-235 in Ben's analogy. It might also be unrealistic, but I wanted to bounce this idea off the community and see what everyone thinks. Who knows, perhaps it sparks a new, better idea in someone else's head. So here it comes.
It's still pretty much a vague idea, but perhaps an entry exam of some sort can help. Not to increase the number of experts per se, but to decrease the number of pop-sci philosophers and no-effort homework posters. Nothing too fancy or long, just a single question requiring a certain level of insight.
Or perhaps a couple of questions requiring varying levels of insight/knowledge. Still not taking too much time or long calculations though, that will decrease the number of new users on all levels of expertise. But their answers to these few questions can then be used to roughly assert the level of the new user and perhaps award a badge corresponding to this level. This way the inquiry ('exam') sort of seems worth the trouble (little more than without the badge anyway) and other users can also more easily determine on roughly what level to answer this new user's question and to what degree to trust their answers.