For muslims, Mohammad was the "perfect man" (al-insan al-kamil), and the example they are to emulate. Their self declared "true believers" take a look at the vile example he set for them, and do just that, so the elimination or rewriting of all the intolerant verses of the Quran and will never be enough. Besides, it's bidah.
And Muhammad thought he was insane and considered suicide...which probably is the root of Islam considering suicide as acceptable.