Most organized religion carry too many similarities with cults. Dietary restrictions, moral obligations, money/food donations, social restrictions, relationship restrictions... And most of these rules are completely arbitrary, often carried over from archaic times when they made more sense.
Then there's the "I'm absolutely right and there's no fucking way I'm wrong, even though I was never involved in the aforementioned events or alive during them" attitude. It's insufferable, and even more so from religions like Christianity. It's not even the most commonly believed religion, yet they believe that they're right and everyone else is wrong, including the most popular religion, Islam.
But Islam isn't innocent, either. Between Islam and Christianity, I'm about ready to stab the next person who tries to convert me. I'm not a mindless thrall for someone to program, I am a person with his own thoughts and beliefs. At least Hinduism doesn't believe in suggested conversion, they believe everyone will eventually job the right religion (which is, if course, Hinduism).
And finally, there's way too much overlapping to be multiple different religions. Something real happened all those years ago, and I'm not saying it was aliens (it was aliens), but something that primitive man couldn't explain was happening all the time. Something else happened, and taking all of those religious texts written by complete morons literally only makes people look dumb.