This happens when "muslims" follow non-Quranic stories and make them to source of religious law.
Those collected contradictory hadiths where written 200 years after departure of Prophet Muhammad.
How can a Muslim rely on them, While in Al-Quran Kareem it clearly says:
2:170 When it is said to them: "Follow what Allah hath revealed:" They say: "Nay! we shall follow the ways of our fathers." What! even though their fathers Were void of wisdom and guidance?
6:114 "Shall I seek other than God as a source of law, when He has revealed to you this book fully detailed?"
45:6 These are the revelations of God, We recite them to you with the truth. So, in which narrative(Hadith) after GOD and His revelations do they believe?@Oberyn
Fact is there is no muslim faction or school anywhere on the entire planet that does not follow or addopt some of the (various and often self-contradictory) Haddiths. ...
Actually there are Muslims who reject the hadith, and they are growing in numbers (e.g.
http://en.wikipedia.org/wiki/Quranism).
All those factions/doctrine's/madhhab's are introduced long after Prophets death. Even if all people on earth would believe in one of them, this wouldn't make it to an authentic source of Islam.