Unless you or your kid has had a coach that has behaved oddly or badly through no fault of the student's, you simply won't understand a situation like this. There are many ego reasons why coaches get weird and start to behave in seemingly illogical and counterproductive ways. This is known as cutting of your nose to spite your face, and yes people do it. Our coach seemed to have felt he had the authority to coach because of his own good high school performance, but when the best runner on the team finished higher in a state meet than the coach ever did, he went psycho on the kid. The guy also really undermines freshmen and sophomores who beat his juniors and seniors. He probably thinks that it makes him look bad if, after several years of his superior training, they aren't better than a newcomer.
Anyway, I like the earlier suggestion that the coach ask some of the other girls to stick around to train with your daughter.