The Architect is probably the oldest machine seen in the movies, other than Deus Ex Machina at the end of M3. The Architect designed (and continues to update) the Matrix. He also balances the equation - the same equation that the Oracle "unbalances."
The Architect hates the Oracle's choice model even though it is the only known solution that "functions" for the Matrix. Choice for humans also means choice for programs, and choice for programs usually leads to denial of deletion. This would be frustrating for anyone, but especially for the Architect, a machine "bound by the parameters of perfection."
I've seen it suggested that the Architect is choosing to play the Oracle's "dangerous game" when Neo chooses the wrong door. He probably knows the Oracle is responsible, but at this point he has no idea what the game is all about. If all possible outcomes of the situation were calculated by him, I doubt even the billion most likely outcomes would include the one that the Oracle had in mind: Neo and Trinity making it into Machine City, Neo plugging directly into Deus, and through Trinity's death, Neo being willing to allow himself to be deleted right before allowing Smith to copy over him (which allows Smith to inherit the deletion). The odds of all this happening would be something astronomical (even for machines), probably not something the Architect could have dreamt up in a million years.
Also, even if the Architect did immeditaely recognize that this is a "game" rather than just senseless human irrationality, I don't think he has the permission needed to just say "game over" and restart the Matrix at will. He's the designer of the Matrix, but even the Architect was built by some other machine and given the purpose of building the Matrix. Even he must answer to Deus Ex Machina, who seems to be the "boss" of all machines. The Architect is just one of many machines doing what they're told to do.
And even if the Architect did have permission to do what he wants with the Matrix at whim, shutting down the Matrix at that time would be irrational because he can still allow the Matrix to continue for a couple more days. He would choose to maximize the amount of energy produced by humans before scrapping everything.
| Architect: TV Screens Architect: Equation |
 Keymaker |  Architect: TV Screens |