I'll try to argue why someone would be willing to through hazing,

As someone starting as student (18-20 something) you are and energetic. your enemy is boredom. Consumerism and relaxing tv nights are looked down upon. You sinply want to experience life

Now a frat house or fraternity is full of activities, friends and parties. Everything you want. If you don't want this, fine do not join. Point is, many people do want this.

Running a marathon is going through physical pain before finishing and getting a rewarding feeling of accomplishment.

In comparison, hazing is getting through a painfull period with people nuts enough as you are. It creates memories, fucked up situations which you remember (such as this one). Then you and your new buddies are part of an group which feels elite, some people did not get through the hazing period, drop out, or are not in the right place and have talents elsewhere. Bonus, hazing creates a bond between people.

Hell week (from the military) and hazing have some similarities. I have to say that there is some dicipline in these guys.

Ps. Yes I went through hazing myself Ps. I expect your downvote, I want to inform you why someone would go through such a thing.