Because God Strongly Opposes
Since Genesis 5:2, Matt. 19:4, and Mark 10:6 state that "God made them Male and Female," no truly God-fearing person could ever violate God's design for mankind and support transgenderism. It is so sad to hear a girl say that she wants to be treated as a boy or vice versa no matter what the mirror on the wall and science says. It is even sadder to hear others say that these same girls and boys should be encouraged to retain their disillusionment. It is almost inconceivable that a school would require everyone else to be complicit in this "lie of the ages" and accept the proposed transgender mandates.
Most school officials are doing this simply to be politically correct which is not a good reason if they were to be honest with themselves. However there are some that are really wanting to show love to these unfortunate students. My answer to them is "love is not love if it sacrifices the truth" and don't let the devil deceive you into thinking otherwise.