[mavidser]

I can't agree that "global public square don't work for humans" - but even if that were the case, it's still too late to just reverse course. As long it's possible, viable and largely desired, the market will spit out a solution to this need.

[nomdep]

Is not too late at all. If you remove the "is not my responsibility what my users publish" for forums beyond X thousand users, every forum will stay under that limit and twitter quickly will become thousands of independent sub-twitters ala reddit. No home page aggregating everything, no suggested tweets, no country-scale public square