I don't know. The absolutist view is purely theorical but I'm not sure it's really viable to have public and private spaces be polar opposites on the matter, especially in a world where privatisations are rampant and larges swathes of the new revolutionary medium for communication is in the hands of a handful of companies who aren't exactly too sad to take a knee for censorship when need be (see Google trying to re-enter China recently). On top of the usual limitations that always existed in the public space (yelling fire in a theater, etc...).
I mean if free speech can only be exercised on a soap box in a park, it's pretty pointless.
Democracies are built upon the principle that freedom of thought, opinion and speech and allowing opposite viewpoints make for better government. There's no reason it wouldn't be true for private collectives and we should always try, even in private settings, to keep that principle at heart with as few limitations as possible and reasonable.
I believe that democratic government should always try to incentivize it and not just abide to not stifle it in its lane.
My 2 cents.
(Yes it's speculative, hyperbolic and a bit slippery slope, but you know...)
