Being "silly" tends to make those games boring really loving quickly once you understand how few interactions you actually have with the world.
But it's significantly less boring when all you can do is crash your car into a wall.
Civilians just move out of the way, and you can't fire a gun unless in a scripted gun-fight.
I'm not saying the game should be a silly sandbox, but I can't understand how my brother can enjoy coming back to it when he's done everything, and he can't even prat around.
He's just driving around LA listening to the same dialogue over and over.
Also, in regards to being "silly", it clearly doesn't make games boring really quickly for the average player. Or else there wouldn't be so many people with such large playtimes on singleplayer in games like GTA and Red Dead.
Bear in mind, I'm discussing the ability to be silly yourself. To decide to drive a car down a sidewalk, or throw dynamite in a town, and get a reaction from the game. Not silly in the Saint's Row sense. Although, that said, Saint's Row is also entertaining for a long time given its actually silly gameplay.
