My pet theory about why the Minis sold poorly is that the 12 Mini was released just a few months after the SE 2; I suspect a lot of the would-be Mini purchasers had just bought an SE 2 instead (not knowing the Mini was just around the corner), and are also not a demographic interested in upgrading their phone every year.
Something quite similar to this is a theme in Greg Egan's Diaspora[1]. Specifically the various "flesher" societies and "bridgers" who facilitate communication between vastly divergent groups.
I would love to have a bit more detail on why this is a non-starter, though I appreciate it’s likely that the answer is too complicated for a layperson to really understand.
So why not incorporate blocks as a signal for the ranking algorithm? The simple version is every person that blocks $USER causes a -n modifier on all of $USER's content; more complex versions could scale the modifier with the number of people (or the combined "reputation" of the people) blocking $USER or shadowban them once x% of posters block them.
Open to abuse? Potentially, but so are a lot of community voting features, and reliably muting serial trolls would be a useful feature for a lot of social sites.