In fact, I'd go so far as to suggest that school sports programs are actually part of the problem, and the changes in attitudes among children may reflect something else entirely. I've long said that kids should be left alone to play sports, and that adult involvement in children's sports can probably do more harm than good in the long run. I've long said that kids probably shouldn't play organized sports at all until high school at the earliest, and even then there is still a danger that the development of the young adults will be harmed by the misplaced priorities of the adults who are involved.
I think you are probably right on the money. I have never liked the idea of kids being pushed around by adults rather than being allowed to play as children.