There is not as much dissent as you make out. The things that bind us together far outweigh the things that separate us.It might be helpful to check out on what points these sects agree on, and what they disagree on. How strongly they disagree and on what grounds they make their claims.
Some fundamentals would be, Did Jesus die on the cross for the sin of the world? Does a person receive salvation based on obeying religious rules, laws and rituals? Or, does salvation come by faith in Jesus Christ.
Do we need a priest as a mediator between God and man, or can a man "Meet God" one on one? Is it "right" to worship God like 1.2.3, or is it a,b.c.etc?
Is the authority of the Bible final, or is it up to (say) the Pope, to add to or take away from it's teachings.
So, I think you asked a question that does not carry simple answer, like "the reason is this and this..."
But, from having read some of your writings, this is all meaningless anyway, because you don't even believe in God, so how can one give a satisfactory reply? Trite, I think is the word you like to use, on responses you get.