I agree; I think daily required PE is the government's attempt to teach kids a healthy lifestyle and sadly, I've never see PE come close to doing that if a healthy lifestyle is not practiced in the home, or if the parents do not provide sports/exercise opportunities to their children outside of school. I'm pretty sure my kid who is in gym for 20 hours a week already plus on a soccer team is getting the message that regular participation in physical activity is valued by our family.
I have personally seen some of my DD's PE classes where half the kids were dragging their feet, make no effort to actually play any activities competitively, etc. Maybe it's age related (she's in 7th gr) but now there's plenty of kids who don't want to work up a sweat or mess up their hair, are too self conscious to put effort into it because they don't want their lack of athletic ability to be front and center, or otherwise use PE time to act out behaviorally. So, yeah, so much for good clean fun at PE. My older DD experienced the same thing in middle school at a different school. Also, it's just not a priority to me for her to be taught sports' rules as part of the academic day (she is well versed in many sports already, but even if she were not, is it that important in our sports crazy culture for her to know the rules of badminton?). Also, DD is a very fast runner and generally good at sports...so when she'd come in first in the mile or otherwise did well at whatever game they were learning, there'd be comments about her size (the comments range from 'yeah, you run fast because you're the size of a 3rd grader...or the opposite 'can't believe some as small as you can run so fast').
I think half the parents want PE so their kids get some energy out before coming home, which is understandable...I certainly appreciate that about PE when it comes to my younger son, for whom 3 outside sports is still not enough to quell his energy level. But sometimes, I feel we lose sight of the forest for the trees. If the goal of PE is to 'give opportunities to learn motor skills, develop fitness and gain understanding about physical activity and its' benefits'...well, I think that can be covered without requiring PE for 12 years depending on the child. I prefer the school shows that it considers the whole child by seeing that for some, those few extra hours a week to do school work instead of PE are much more beneficial to a student's academic growth and physical well being.