I see no difference between "promotes" and "rewards" here. If it's a difference of intent, I'll point to everyone in this thread consciously "promoting" a lifestyle of fewer working hours, cleaner food, and less driving as a much more salient viewpoint than the opposite. And if the difference is because of "the system", well, you're going to have to differentiate between the system of living in human society and ... some subset of that system, I guess. Some subset

Luckily there's a precise term from economics we can use here to split the difference: Opportunity cost. I can certainly concede that in some people's lives the opportunity cost to working out is higher. In some lives you make a lot more money per hour worked than you do working out, and so it's not a surprise more people on the margin in those situations choose the former over the latter. If you dislike even having that option on the table, the good news is you can move to someplace where you make less money, and then that opportunity cost will go down, because working out is pretty much the same wherever you go.

One more sophisticated take of course is to claim people don't really know what's good for them, and they discount the true value of working out far too heavily. (s/working out/eating less/g, or whatever other health promoting difficult activity you wish to sub in here.) But, if we're going to claim that -- which is actually pretty reasonable -- then why would we consider a miracle drug that seems to directly counteract that irrational discounting a bad thing? That should be a godsend.