Well, I feel that there's some truth to it, but that would be more like "Dumbed down for the console controller" than anything.
The reason most people say "dumbed down for the console gamer" is that console gaming is the mainstream, and everyone likes to think that they're better than the majority of sheep that go with the crowd, even when they're just sheep in a different crowd. Also, PC gamers usually resort to fanboyism rather than admit that consoles and PCs are both great for playing video games and that neither is better than the other.
The reason most people say "dumbed down for the console gamer" is that console gaming is the mainstream, and everyone likes to think that they're better than the majority of sheep that go with the crowd, even when they're just sheep in a different crowd. Also, PC gamers usually resort to fanboyism rather than admit that consoles and PCs are both great for playing video games and that neither is better than the other.