We all have been awaken by different things. For some, it was the Pyramid. For others, it was the handling of sexual abuse cases.
Believe it or not, I knew about the pyramid, the UN association, the sexual abuses cases, the flip flops in teachings, the wrong date for the destruction of Jerusalem (607), the 1975 teachings and subsequent denial of these, and so on.
I knew of all these things and I simply rationalized it all away, thinking that in the end, they were doing more good than evil.
Then, I had kids and I had to face the fact that the WT would not allow me to teach them based on my conscience. It would have to be their entire program, otherwise, I risked being disfellowshiped for apostasy (I envisioned at least two scenarios would lead to this). The thought that my kids would indirectly have to be thought by man that were essentially threatening me was the final straw.
That is when I left. Since then, I also came to understand a few more things that solidified my current position.