Other than entirely community-driven projects (like https://wanderer.to/ mentioned in the article), are there company "forms" that legally protect against this kind of sell-out? Like non-profit or public-benefit-corporation? If users are contributing the content of the app, it seems they should have a way to hold the owners accountable.
Unless you already have large interested parties "bribing" (not technically of course) the group of controlling members tends to be a weakness of anything crowd sourced.
Especially since it is rarely cut and dry. If the finances aren't working out is it better to sell and keep the site online or not? Are intrusive pop ups begging for donations a better option? There isn't a singular true best option.