Here another way to look at this advice:
Everyday I run across the road without looking. It's exhilarating! It makes me feel ALIVE! I know all you naysayers say that I should look before crossing the road. I just rip off the band aid and fucking yolo it. I haven't been ran over by a car yet!
Really stupid. My advice is don't listen to this advice. If you are getting itchy feet go on a fucking holiday for a few weeks.
You could also call this quite myopic. How do you know what is out there without trying it yourself? Sitting in your little world and poo poo'ing those who are willing to take a chance. Because yes, from their vantage point, OP is right.
There really is a world out there that few can find but it's worth looking for if you have good reasons to take a chance and put down new roots. Most don't make it because accepting any culture outside of the one of your birth is a very difficult task, and you will never have any true change until you accept a new culture: their customs, their values, their belief systems.
Because really there is quite a lot of variation in those things, and in all the travels I have had, I have only met a few who truly made it. And there is of course a loneliness that comes along with the change, at least for a while. That doesn't mean it isn't worth trying, and if you bit off more than you can chew, just go back home. You obviously need resources to do that, but it's not really as scary as you make it out to be.