Like your son, I thought K would be a complete waste of time for my son. I also got the big socialization speech. As it stands now, DS is in K very little, but I do think it was useful in some ways.
He learned "how to do school". He learned a bunch of things like using scissors and writing on the lines. He does Art and Music with K. Funny thing about the social skills... Through their own observations, the school determined that his social skills were fine in all of his classes with older classmates. His only issues were with agemates. However it was observed that he does fine with agemates at recess. Within the classroom he is usually alone.
It sounds like the school is at least trying to get it right and many adjustments will have to be made once school actually starts. But have faith and give it a little time. Schools are very slow to step outside the box, but will eventually make a move with a good argument.
