Why can't politics be like the real world ?

In my experience in the "real" world when someone hires you to do a job they give you a set objectives and you have to produce results on those objectives. If you don't you're fired. Why can't we do that with the politicitans ? Give them objectives and a timeframe, on the due date, have them stand before us and speak to the results, no excuses, no mud slinging, just results. If they don't produce they're gone.