Erm, why should there be any "discipline" at all?

Discussion sites (HN included) exist solely due to their users' laziness for using and/or creating better Free decentralized solutions and ensuing network effects. In exchange for this ease of use, the site inserts an epsilon of advertising and censorship. This is the extent of their value proposition.

Eventually business/legal skinjobs take over, mistake the community for an owned golden goose, and ramp up the amount of advertising/censorship. The illusion of openness is shattered. The users revolt and move to the next green pasture.