There are many reasons some contra dancers don't like squares. One
is that they take a long time to teach. For some squares it's a good
idea to walk through the figure for both the heads and sides.
Depending on the caller and dancers a full length break may be taught
as well.
When I call where there are both beginners and square haters, I look
for quick teach squares. One that comes to mind is Reel Your Partner
by Ted S.
I also highly recommend squares written by Tony Parkes. He's written
many that are accessible and a the same time interesting.