This "why should I care" is something that comes often about him. And the answer is basically, well, you shouldn't particularly care. He's just one person like another giving his thoughts about the game, with a clear negative slant. He's just part of the real-life-social-media-mmo that SC is first and foremost at this point in time. Yes, his name or his posts might come up often. That's because he seems to have some issues with his games not being as successful as he'd like, and therefore tends to enjoy slamming the "competition" if he spots an opportunity to do so (and well, let's be honest, SC makes it easy). He's making some interesting points (whether you deem him successful or not, he developed and published games and makes a living out of it so he does have some expert insight in the domain that shouldn't be dismissed), he's making some bad ones, he's making a lot of hit and miss predictions, and like any other online source, you might or might not enjoy his stuff.
But that, in itself, wouldn't have been enough to make him the online equivalent of a B-grade celebrity. Somehow, the good folks behind SC didn't know the
Streisand effect was a thing and revoked his pledge to get rid of him on their forums. The result is what you see now, he's even more vocal, and due to the amount of regular content he publishes about the topic, has gained some sort of fame in the social circles around the game. I mean, there was a time on the SC subreddit where they talked about him like Voldemort with "you know who" and "he who shall not be named". You can't make up that stuff. Even the folks who think he's meaningless treat him like some sort of mystic foe whose name itself can spell doom.
That's all there is to it really. He's just one person like all of us, making some good and bad points. He's just more zealous about it, to the point where if one is reading about SC, it's likely you'll end up seeing some of his posts linked or referenced. Ideally, his
posts should be discussed, as opposed to his supposed secret agenda or personality, but well, he's been turned into a scarecrow so...