It's justifiably characterized as biased. We lose a useful term for distinguishing normal bias from marketing or PR instigated efforts. That's the point of the term astroturfing. It's useful in that regard. Or I suppose, if it's definition has truly shifted, was useful.
Can a stand-alone complex be an astroturf? I think so, if the social conditions that create the behavior stem from a single entity that stands to benefit.
The point of astroturfing (in comparison to the term it derives from, grassroots) is that it's not people coming together to support a policy, it's people with a vested interest in an entity taking cues from that entity to act in their interests in such a way that it appears as the former. The definition never shifted, the tactics just became less obvious. I would be less suspicious if more comments were complaining or giving measured thoughts, but they weren't.
If I may really stretch the metaphor, I'd say individuals with vested interests are more like sod. They really hold those opinions, and are motivated to express them, but do so "unnaturally". Vs commercial efforts that are entirely fake and are therefore astroturf :D
