"Fan cluster" is a made up phrase. And a bunch more words.
All phrases are made up. In this case, I made it up to signify a grouping, not too large, and irregular in shape. Your argument is that a vocal little cluster is a lot of times somewhat indicative of the larger gamer hive mind. That's vague and not really backed-up by anything. If ti turned out the twenty people complaining on the forums had their complaints addressed, that doesn't mean they were or weren't indicative.
You're actually suggesting it's less risky to piss off television fans than gamers? No. Television still has stupid wide reach. Do you know, for example, where Jobs had Apple spend most of it's advertising budget? TV. TV talks to the hivemind of the world. The few people yelling about Ubisoft and always online are a tiny fraction of those annoyed by something like Firefly, Terminator SCC or Dollhouse. Or anything else Summer Glau has had cancelled.
Making your fans happy in TV land is much, much more vital than in gamer land. You pay in time for both, and emotional attachment to your favourite show. Crossing TV fans is riskier than offending gamers. Nielsens and the advertising dollars they bring in demonstrate that.
You watch and see how much complaining about Watch Dogs graphics or anything else on the forums affects sales. You might recall similarly angry postings and yammering about Call of Duty being the same or a thousand other CoD complaints while the game sold like mad.