Because it is constitutionally impossible for me to run for president. It is not difficult to stand up in front of the country, tell them you'll do something, then actually fucking do it. If I were ever elected president, I'd be assassinated immediately because I wouldn't be playing ball with anyone in Washington who isn't answering to the people. I don't really care about deadlines on funding bills, unless you can justify every penny in that bill to the satisfaction of the entire country, you can shove it up your ass, etc.
The problem is first past the post voting. It is mathematically highly improbable that any candidate outside of the two parties would ever be elected. And so long as the corporations making up some large % of our national GDP are funding those two parties, they will never again accept a candidate that isn't in lock-step with those paying to put them in power.
The Problems with First Past the Post Voting Explained - YouTube