I'm of the opinion that this problem is a more modern incarnation of an ancient problem: most people just don't find any pleasure in thinking.
The central message of this piece isn't just a matter of saying we ought to create our own leisure time, but that our leisure time ought to be more contemplative, and this message isn't just a matter of developing more leisure time, its a matter of prioritizing sitting and thinking over acting.
What I think this piece wants to say is that if we got rid of our work-central culture and our email accounts then we would default to a more thoughtful state of being. I think this is much too strong a claim than the piece can support, because before the internet most people still spent their time doing things instead of examining their life.
I mean, we may have a bit of a sampling bias, when we consider past people, because we only ever really hear about the people who enjoyed thinking enough to make or do something that persisted until this day, but there were plenty of people who avoided having time to think just as there are today.
What I think is, on the whole, those who legitimately enjoy thinking are going to find the time to do so no matter what their life circumstances, and those who don't, won't.