Now, you can constantly prod yourself to run on a wheel too, figuratively speaking
That "figuratively speaking" is really the key difference between you and those mice though, and where the argument breaks down.
Is it really good health advice to force yourself to do exercises?
Define "forcing". In the article, "forcing" refers to physically forcing the mice to do exercise. It would be the equivalent of me throwing you in a cage that has a treadmill for a floor, and you can't get off. No, that's not going to be a productive way to exercise. And I also suspect the stress of the situation might cause you more harm than good, as it did those mice.
When someone gives you the advice to "force yourself" to exercise, it doesn't refer to physically forcing you to do it.
If and when we recommend "forcing yourself" to do something, we mean that they should do something even though they don't want to. The benefits of leaving your comfort zone to, for example, go to the gym, are well documented. Going to the gym and working out is for a lot of people, myself included, still a chore after over a decade of doing it.
Working out is difficult for a lot of reasons. But that's the "outside the comfort zone" bit. If it was easy, you wouldn't get a challenge, and without a challenge you're not improving.
Suppose I ditch it. I'm going become weaker, and my flexibility will suck in several months' time (it already does, with all them sprains and whatnot), that's for sure. But will I become healthier, counterintuitively?
I wish! I'd stop working out too!
But no, definitely not. Even if you're prone to sprains, working out would be a recommended remedy, since it benefits bone health.
And a sedentary lifestyle doesn't just mean not growing muscles. It means losing muscles. It means deteriorating joints and back and neck. It means chronic pain before you're old enough for it to make sense. It means clogged arteries and early organ failure. It means your body feels heavier each month, even if you're not gaining weight.
I know what you are going to suggest, "find something you like". As if it was that easy
I'm right there with you. I didn't really enjoy going to the gym and doing the standard lifts either. And there are other people on this site who are gonna give me a hard time in the chat rooms after I've said this. :D
Personally, I found my salvation in climbing. Sport climbing, bouldering, both indoors and outdoors. I'm always itching to go climb. But I agree that for us to sit here and say "try this, try that" is not going to be helpful. All I can say is try something. And if you don't like it, try the next thing. That's getting outside your comfort zone, and you'll hate it for a while, so you'll be on the right track at least.