Shorter Intense Workouts: More Effective or Just a Time Saver?

We increasingly hear more about the benefits of shorter, more intense workouts and less frequent exercise versus longer, more frequent workouts. Traditional exercise guidelines have suggested for many years a recommendation of 3-5 times per week of exercise for a minimum or 30 minutes per session, and preferably 60-90 minutes total per day.
More recently the research has suggested that high intensity intervals can be more effective than longer duration, lower intense workouts. In the past few months, however, articles have touted the benefit of minimalist workouts, such as 16-30 minutes total per week dispersed into quick intervals, such as 5-6 minutes per session of all out work to rest ratio of 30 second intervals, such as 30 second sprints repeated five or six times with brief rest intervals in between.
While I support the high intensity interval circuit workouts, and especially functional training, I wonder if these recent statements and findings reflect not necessarily sound research, but a desperate attempt to get people to do something, as the number of Americans who are active continues to drop to a now low of 20%. Coupled with that, the percent of Americans who are also overweight or obese continues to climb.
What do you think?  Valid research or desperate attempt to appeal to Americans to get off the chair, couch, and just do something?......