As far as I can tell this is a side effect of optimizing the algorithm to encourage greater usage by discouraging limited usage. Asking FB, Twitter etc. to do any different is the same as asking them to make less money.
You'd think that FB would want to pull "wayward" people in, though. If I haven't posted in a while, and then suddenly post, FB should give that post wider reach, with the hope that I get a lot of engagement, come away with a positive feeling, and then post/engage more.
I just did a sort of impromptu 2.5 month posting hiatus from FB (which also included no commenting or liking), and when I returned I got a ton of likes and comments on my fist couple posts.
The thing is, these places aren't monolithic. Real people work there and are making real decisions. There is more than enough room for Facebook to be reasonable and still have plenty of pie, it's just that employees need to actually make themselves heard or make the right decisions.
I just did a sort of impromptu 2.5 month posting hiatus from FB (which also included no commenting or liking), and when I returned I got a ton of likes and comments on my fist couple posts.