While I understand the OP's concerns, I can still see the benefits of teaching some sort of music to kids.

Some kids will probably never progress past the basic ukulele strumming stage, but the chance to open their minds to what makes music, the component parts like rhythm, melody, singing etc and the joy of making music together is too good to pass up.

For the kids who progress past the basic chords and strumming, who learn what music notation is, that melodies can be picked out, fingerpicking styles can be used, the uke can accompany other instruments or singers, and they can join in at the community uke learning events, groups and festivals, then the uke is a stepping stone to a world of infinite musical possibilities.

Some kids have musical opportunities because their parents can afford music lessons, but a lot of kids don't.

Looking at it as either the majority of kids get no music opportunities at all or they get a window into the musical world with the options to move forward if they wish into more skilled areas and maybe even rock fame, fortune and the rock lifestyle (joke, in case you are unsure), then I would opt for any musical playing experience at a young age is better than none.

When my sister and I were in the last year of primary school, our teacher taught the class a plastic whistle closer to a penny whistle than a recorder, because the notes went up the scale in a simple manner, not the fancy digital footwork required of a recorder (which I don't play). We learned music notation so that we could play melodies and maybe even some simple harmonies, and we learned to play together as a group, and we even performed at the school assembly a few times. When we had a school reunion about 30 years later, a few of us brought our plastic whistles along and gave a brief performance for the teacher.

Going back even further, we had a music appreciation class in infants school. We had the whole school in one room - only about 50 kids - and the head teacher would give us a lesson on music and musical instruments, and then we had a percussion "band" which I imagine sounded fairly dinky but we had a lot of fun and from the age of 6 it opened my eyes to music and its possibilities for me. I began to see the link between what I heard on the radio and how it was made.

All through school we also had the national radio broadcast of the music for schools programme. There were books supplied with music notation and lyrics for the chosen songs for the year. I believe at least one prominent folkie named Chris Kempster was "instrumental" in getting this programme started.

There are some very good ukulele community-based groups here in Australia, and one of the best (IMHO) is right here in my own regional city. There is a real wave of DIY music here for children and adults of all ages, which I can only see as a positive thing.