I feel you could make the same argument re: stenography?
I think over 18 years of education it's reasonable to teach kids both forms of writing.
There is no lack of curriculum space.
Most things we learn we forget. Writing is one of those neat thing we keep forever.
Hah! You must be a young 'un. My handwriting has deteriorated over the years, from a pretty bad start. And "neat" would be an eccentric description of my style.
And if you had to do it for more than 3 days, your skills would be back.