The Gaussian depends upon a notion of independence and identical distribution: independence can be dispensed of when one thinks about power laws.
If you can soberly state the assumption that the effects of a comment on any other comment is completely negligible, or falls into a couple of other strange exceptions that leads to the universal phenomena that generates the Gaussian, then and only then can you state that any quantity associated with comments is Gaussian. I do not think that this can be soberly stated as such.
All this said, I'm hugely and awesomely excited by the future prospects of becoming a multiplanet species.
(That doesn't mean that it will follow a Gaussian distribution, just that it could be defined in a way where it makes sense that it can sometimes be negative.)
Pedantic point aside, you bring up an important point. Can behavioral incentives be aligned to avoid the bottom side of participation?