It's obviously done for fun, not for a technical reason.
I did that only a very few times, and so probably do the guys you are referring to.
Under certain particular conditions (loooong runway, light weight, rear CG) sometimes you do that just for fun, because you
feel it's almost coming by itself... I mean, you didn't plan to do it, but decide on the spot.
You hold it up longer than normal until you
feel it's time to drop it safely.
Yes it takes some degree of skill.
Once again, we all agree it's not good practice
routinely , it's only done for fun when the conditions permit.
One day I did that in EDDM, and the controller told us "Nice wheeling!".
It was the first time I had heard such a term.
Another theory I heard long ago in darkest Africa, after I saw DC8s doing that routinely, was that you save a little bit the nosewheel tires life.
I didn't consider it worth adding that technique to my background, though....
