I think it became a popular notion because people want to have a sense of control in their lives, especially in the fearful and lawless times we now find ourselves living in. Moreover, in a disaster, where things are logarithimcally worse, people want to believe they can take charge and not be a lamb led to slaughter.
But, as mentioned, so much of the "bugging out" culture does not consider the hard cold facts of reality. Some people say they are going to "stash" food, water, and medicines in the woods. Really? Where exactly? Are they sure they can get to them in a true disaster? How can they ensure their "stash" is safe?
One thing that has been mentioned by former military who have been out there, lugging their equipement around: stuff is HEAVY!
Also, if you have small children, and older person with medical issues, or a pregnant wife, all this talk about "living off the land" becomes even more unrealistic. I am not saying it could not be accomplished, only that it would encounter great difficulty.
That is why in many disaster, people turn up in shelters.
They tried it on their own, and many didn't last but a few hours before they headed to the nearest designated shelter area.
I saw a few of those during Katrina. Not......Fun....Places.