You are still racing cars, you are still playing football with the safety gear on (although football players in Australia do not wear helmets, and F1 cars don't have roll cages nor even roofs). Perhaps your analogies are off also ;)
However, you can climb mountains in different ways and people want to explore the possibilities. Some climbers think bolts are OK, some don't. It's their personal philosophy. They don't get the satisfaction they want if they use bolts, and think they desecrate the climb. So they don't use them. Not because they want to tempt fate, but because they would prefer not to climb things in that way.
The reason you ask for is: It's what they want to do. Reinhold Messner climbed mountains without oxygen, without seige tactics, because that's how he thought mountains should be climbed. Not because he wanted to tempt fate by eschewing "safety gear".
Wingsuit BASE is much more dangerous than regular BASE. Putting on a wingsuit is the opposite of safety gear - it's dangerous gear. However, it's not done to tempt fate, it's done to gain a different experience. That's what I think Honnold is doing here. He thinks it can be done, he thinks he can do it, and he turns out to be right. Same as Messner.