Because any defense of being able to orchestrate a professional coup and do your other work with the same zeal and focus as you did before fomenting rebellion I take as seriously as people who tell me they can multitask effectively.
It's just not possible. We're limited in how much energy we can bring to daily work, that's a fact. If your brain is occupied both with dreams of king-making and your regular duties at the job, your mental bandwidth is compromised.