Mixed Message?

I have had many occasions to wonder about this:

If we are in fact as concerned about childhood obesity and inactivity as we claim to be, why then is exercise still handed out as punishment?

They did that sort of thing when I was in school, back when we still did our homework on the back of the coal shovel next to the fireplace, but nobody had heard of childhood obesity back then so nobody cared. However, when my kid comes home now--in the supposedly enlightened twenty-first century--and recounts the insane number of push-ups or laps that were assigned for some transgression (usually pretty dubious, at that), I have to shake my head.

What sort of message does it send to use exercise as punishment, and then wring our hands because our kids don't like to exercise?

I think the message is that we're screwed up.