It's not because nomad life is so great, often it's because they struggled because--again--life in developed areas is tough and so they opted for the easier way.
Moreover, those have still some home base in an developed country, a back door where they can always settle again, so it's not really nomad, it's just a long vacation labeled as something adventurous.
For us from developed countries, it's so easy to take our backpack and travel dozens of countries and just spent a fraction of what we would spent in NY, London or Berlin. You know it's really nothing special or something people should admire. Everyone from a developed country can do this. But nobody from not so developed countries could and want to do this. I personally would miss a goal and again the challenge. I can just buy a ticket in 5 minutes and go, find some remote work and live for peanuts. Where is the problem, everyone can do this There is no risk and no goal. And because your FB friends got tired of all your useless and boring nomad posts you need to write now public blog posts and spam social news sites telling people that what you do is great justifying your goal-less endeavour to yourself.
So, another popular reason of being a 'nomad' might be: I am struggling with the high competition in my current environment, want to save money or spent a fraction in an underdeveloped country and live like a king. But not like I want to know who I am (maybe they know it afterwards but I think it's rather unrelated).
Not all of us want to escape. We just want to see the world and learn. I grew up in a small town, I dont have a place I could call home apart the earth...
On the other hand, I know there is an increase of people that want to escape, but maybe they have a reason to do it. City life is not for everyone. Many of us want to have a slower life, cherishing small things in nature and learn about the world directly, without intermediaries.
And I dont think is about struggling with the high competition or have a cheaper life somewhere else. Some of us just prefer to have a different life style. Some people chose to have 2 cars, a house and lots of stuff inside, some others just prefer to have only one backpack with their belongings in it and move slowly around the world...
My point is that there is not one way of living. I was raised in a way where I had to follow just one path but seeing people living differently made me realize the diversity of lifestyles and made me aware of so many options in life.
Which is exactly what small town life is. No need to go nomad for that. In my experience, backpacking is neither slow life, nor cherishing small thing. It may be compared to multi-million city, but it's not compared to living in small town or village.
Backpacking is not black or white. There is backpackers who multihop cities every couple of days to get laid in backpacker hostels, some others travel slow, some to remote places, some others move where there is food and work, some others follow adventure, some others backpack while volunteering...
Also, this life style is nice for getting to know yourself, what do you really want? Maybe you thought you were a city dweller but now you know you feel better closer to nature. You also learn that you don't need much as a human, that is a very comforting though that can get you through difficult times.
Changing your lifestyle may not always be pleasant (at first) but you learn about yourself. For example, I though I was a real backpacker, turns out I get very stressed when I have to get in random taxis and I convince myself almost everyone wants to screw me (in the bad way) and I have constant inner dialogue about why I would care about being screwed for a couple of euros. Now I plan thing differently, maybe I someday really learn to relax. But it won't be by sitting at home, I know that for sure. For now, I have kids and already learn that I don't like my life style to adventurous (maybe I'm not even that adventurous without kids), and I'm ok with that... even though that took some time to accept.