Recipe for divorce. You marry because you've found the person you want to spend the rest of your life with, and that has nothing to do with what "time" you think it is. If you marry the closest warm body because "It's Time to Get Married", you're in for a rude surprise.
Well duh, no man is going to get married until he feels it's the right time.
I think you're making a wrong distinction. When you've found "Her", I think you pretty much know who you're going to marry. After that, you still have to pick "the right time to settle down" with her. After college, say, or some "decent courtship interval."
I don't think most of that 81% decided to go out and find a prospective bride after the time was right.
I think some men pass up great women because they just don't want to get married at that time.
I think that's okay for a guy in his early 20's, but when they start hitting their 30's or 40's then I think it's a problem.