I'm not sure I'll ever agree with this thread's principles.
I mean, weak protagonists are part of what makes my gaming experience fun. It's fun being a fairly weak martial artist with only a stick, a camera and a watch with a crossbow with all the strength of a pea shooter to bring down a galactic conspiracy. It's fun being a nerd, a thick biker and a slightly insane science student as they stop lab experiments messing with the space time continuum. And yes, its fun playing a Janitor in space.
This is all because THOSE protagonists grow on you and turn into thier own unique brand of badass throughout the course of the game. Its the kind of badass you'd like to see paired up with Stalone and Schwarzenegger in the same movie and have them praised by the critics for being a convincing, larger than life character who brings thier own unique brand of badass to the movie.
Now there are a lot of times I feel like I could have done the job better myself than the protagonists when they mess up, but this just adds to thier character - no ones perfect, everyoen makes mistakes, and yet after all that they end up saving the world anyway. No one character I have ever seen in a video game that I've had to control has been so out of control of thier situation that I personally feel I could have done a better job of thier game if I was airlifted into thier place. They're either so pumped full of steroids they could arm wrestle God to a standstill after eating a machine gun bullet sandwich, or have too many redeeming qualities to replace thier macho that I simply couldn't match.
...
Okay there's the entire cast of Resident Evil... but otherwise my point stands.