This is true, like anything, you need to build up to it. I lived an entirely sedentary lifestyle for the first 30 years of my life, hated all sport and physical activity. Dated a girl who taught me the joys of exercise and movement and I've been hooked on running for the past 4 years.

Takes some time to build up a base, and of course you need to be careful if you are quite heavy initially like I was. If you just listen to your body and don't overdo it, it all comes together pretty naturally. While bad form is a risk, a lot of what I've read seems to indicate that your body will naturally find a running gait that is optimal for your body and minimizes impact. Running without headphones also helps, just listen to your footfalls and adjust your stride to minimize impact. (I can't find any studies on this, but I can't help but feel that a lighter footfall is likely minimizing impact on joints somehow)