I get it, I don't do it with a spoon, but I understand the problem it's trying to solve.
Most forks are curved, so you naturally pick up the pasta so it lands in the concave side, but when you flip it over to start spinning, the pasta slides off the end or down to the handle. So it becomes a shitty game to try to keep the spaghetti on the fork while you twirl it to fit the whole thing in your mouth.
There's a few solutions to this, like spinning the fork against the plate or using a spoon, or a fancy spaghetti fork (like in the OP). I'm sure there's more, that's just what I can think of.
I have never seen this. italians spin their fork in the spoon to wrap the noodles, seems to work fine. That spaghetti fork would have terrible mouth feel.
Seems like a common thing in North America. I've seen plenty of people use a spoon to hold the tip of their fork to spin it and ball up spaghetti (and similar noodle pasta).
I'm not even Italian, I think it's weird. Far be it for me to tell anyone how to eat though. So I just shut my mouth and eat my spaghetti, my way.
Could be, an old Italian guy showed me the spoon as the base and fork as the spinning tool. But yeah maybe it is regional...or like giving white people a fork at an asian place