I think they did a really intelligent move for "Saints Row 4": The people that bought SR3 instead of GTA4 were those people that wanted to have the freedom of doing stupid things, maybe unrealistic, but great! And let's admit that, Grand theft auto is really realistic, it's good, but it's like having the feet chained to the ground.
So, making everything even more unrealistic and even more.. mad, they're trying to catch again the interests of those kind of buyers. Those who really like the freedom of... Chaos and ridiculousness.