Great whistling fire arrows! I go out to a shoot for a day, come back tired and go to bed and in a day and a night you guys fill ten pages with my favorite subject!
Good discussion, and, as has been said so many times, there really isn't a definitive answer, any more than "Why blonds or brunettes?" Folks differ in what appeals to them and how they react to given experiences. Some try something, don't have a good reaction and move on, others decide to stick till they master it just out of stubbornness. That' was me... the bow appealed and I was determined. It took me awhile to learn to shoot the Hill as well as i could a recurve, and I'm not sure I'm there yet... I'd have to go shoot a recurve!
As to why now, I think over the past few years, Hill style bows have acquired a few evangelical believers who have been beating the drum. (Yep,, guilty here), me, Mudd, Raging Waters and others. The Hill Longbowmen list is about three years old now and they've collected a lot of info for folks. So, there's been a lot of smoke... hopefully, even some fire.
As to hand shock, I've given up. Some folks experience it to greater degrees than others. Personally, it's part of my belief that there is no such thing as an inanimate object, and the bows know when you don't trust them or like them. I just know that they can be built for smoothness. They have narrow, heavy cores and if they're built for max draw weight and speed, a lot of force is going to have to be absorbed by relatively little mass.
I had a guy here for coaching Thursday. He'd been shooting both recurves and longbows. He drew half a dozen of mine and his eyes got so wide the yard lit up! He was having what I call a "chainsaw moment"... (What's that noise?!)
Hill style will always be a small niche but I hope and suspect, always a passionate one. Somewhere in the backs of our minds, when we think traditional, we're looking for a return to simplicity, and while Howard did cross the line (in my opinion) when he added the shelf, which I regard as high tech, what bow is simpler?