I don’t think that’s an accurate statement. Maybe most of the enlisted people are, but a very large percentage of the officers hate him. He is their commanding officer, and they openly insult him. They ridicule him constantly and talk about how terrible his decisions are. They joke about how stupid the SecDef’s plans are. And they do all this in front of their superior officers.

The officers make an oath about defending the constitution, but they also hold very strongly to their duty to protect the people they command. Trump puts those people in jeopardy for no damn reason, so many hate him for that.