Why does anyone do something dangerous?
It could be riding motorcycles (street or track), fast cars, scuba diving (caves & shipwrecks especially), hunting dangerous game, climbing (rock or mountain), and on and on.
The answers are as varied and wide ranging as the people doing it.
The rush, the challenge, the satisfaction of doing something most others wouldn't, the cameraderie of being around like-minded people, and many other reasons.
Dan BC had a quote that bounced around FB a couple years ago. Something to the effect of:
What we do is really, really stupid. Intentionally throwing one's self out of a plane for fun would be the dumbest thing in the world, except for the fact that flying through the air, with no support at all, just you and the sky, is the most amazing thing in the world.
My reasons and responses to the wuffo question of 'why do you do it' has evolved over the years.
Currently, I will answer 'Because it's the most amazing and incredible thing I've ever done, and my life would be dull boring and grey without it.'.
That doesn't discount the risk. I've been around long enough, seen enough and lost enough friends that I understand that any time I go out the door, it might be the last thing I do on this earth.
I have asked myself more than once: "Is it worth it?"
The answer someday will be 'No, it's not'. That will be the day I hang it up.
But not today (well, whenever stuff opens up and I can go up again anyway).