I myself saw first hand how nasty guys can be but for every bad guy I've met, I've also have met really awesome dudes over the years. However I can understand having a serious issue with men in general, since a lot of us go through male puberty unwillingly and are thrown into a man's world. So we're given this perspective that cis women will never have, which creates a whole new level of sexism that's hard to shake.
And depending on when we transition is also a huge factor here. Young transitioners vs older transitioners, there's a big difference in experiences. One has spent decades in the male role, while those of us that are young and transition, only had a short experience of being in that assigned gender. So it ends up making those that have spent so many years looking from the other side, a bit more jaded possibly.
And it should be noted a lot of the violence and hate we receive are often from straight men usually, especially against trans women of color. So with that its kind of hard not to be cautious about most men, since straight men are the majority in our society.
For me personally I love guys, my best friend is male (childhood friend) and hes extremely important to me. Hes always been super caring and when I came out to him, he was extremely supportive. I couldn't ask for a better friend. At the end of the day though, we still live in a sexist society that I hope changes for the better in due time.