I think that a balance is needed when teaching notation. In effect, notation is a common way of communicating music to each other, so it covers more than just the conventional methods of staff notation.
I admit that I do use rhythmic notation quite early on with my Year 7 pupils as I teach with percussion a great deal. I find that by using simple notation, they can use this as a tool in composition. I also think that it is so useful when developing skills such as time-keeping/pulse/rhythm etc and I constantly test my pupils on their aural perception. I tend to use made-up phrases for rhythms,