I give Buffer a lot of credit. They seem to deeply internalize the idea of "realistic expectations" and it sounds like the buy-out was a win-win solution where everyone got (mostly) what they wanted.
As he says, the investors might not have been happy about it, but at least he has the backbone to resist trying to squeeze growth out of a market where there's none to be had (in the short term). Most CEOs wouldn't be as courageous, preferring to try to spend like crazy in the search for growth, which just torches investor capital even as it adds little long-term value to the business's equity.
In short, a bold move by a very honest guy who's in it for the long term.