(1) Monotheism. Orthodox Judaism has become a religion of pantheism which is opposed to the world view of the Torah and the Talmud and the Ari. That would be in addition to the pantheon of little gods they have.
(2) They are not opposed to the State of Israel and in fact do what they can to support it.. I have never heard of a Reform or Conservative person that was opposed to the State of Israel. I do not look kindly on many Orthodox who support the effort of the Muslims to wipe Israel off the map and drive the Jews into the ocean.
These are two important issues. When the Ultra Orthodox not just in word, but in deed try to bankrupt the State of Israel.
When the Ultra Orthodox support Islamic causes, they don't seem to realize that they are supporting people that have every intension of murdering Jews like they have always done and seem to be intent on doing for the perceivable future.[What I mean is the Ultra Orthodox think they are just opposing the political contract of the State of Israel. They want to be under gentile rule. But they don't realize that gentile rule in Israel was never benign.]
(3) Reform lacks the astounding amount of child sexual abuse that goes on in the Orthodox world
The problem however is that for some reason Reform do not learn the much Mishna or Talmud. And even the Conservative do not make it a priority.
And the very idea of keeping the commandments is not on the radar scope of the Reform. Well at least the right wing of the Conservatives do better in terms of keeping mitzvas.
The major problem with Reform it they lack the numinous aspect of Torah.
I think the Conservative movement is on the right track in terms of emphasizing the Talmud but also recognizing that reason and logic and science also are authorities in there areas.
At this point I would have to say that since the Orthodox seems to have problems with facts and reality that it has morphed into a cult. Orthodox have had plenty of time to get their act together, and just seem intent on getting more and more fanatic.