Welcome to the real world. The one where nothing revolves around health and well-being, but instead on your "productivity," and you slowly trade your present and future health for a paycheck. You might be productive now, but as the days, weeks, months, and years go by, you'll find that your body has become so decrepit that even simple tasks become a humbling challenge.
Study after study is revealing that health isn't maintained by an hour at the gym five days a week. You should consider that hour your "pleasure workout" - do it because it's fun, do it because it makes you look good and feel good, do it because it lets you eat dessert, but don't fool yourself into thinking that it undoes 8 hours of sitting each day.
The desk workouts are not only a collection of activities to perform throughout the day, but a framework to plug them into that allows you to maintain or even boost your work productivity while staving off the damage to your health associated with sedentary work and long periods of sitting.