Don't get me wrong, I don't like frats myself, I never really wanted to be in one, but I can see why many would. The main purpose of a fraternity/sorority is to build a bond with other people around you and accomplish things as a group that you may not be able to accomplish on your own. For instance, this often plays out with the ability to throw huge parties that any one of them would not be able to accomplish, but as a group you can pull it off. You can pool resources and get a house. You can spread the word out better. You can work together to make an image that people want to actually attend the party because YOUR frat is throwing it.

The same thing goes for school, though. You often see frat brothers working together to study, to get into project opportunities they may not have otherwise gotten into.

The problem comes when this ideal gets twisted. Sometimes a bad apple gets in there and starts corrupting it. Maybe a guy likes to roofie girls at his frat parties. His brothers SHOULD immediately call out his bullshit and put an end to it - but he might be a smooth talker and convince them it's ok for whatever reason, or be sneaky, and the bros want to have his back on the matter because that's what they've always done, that's why they're in a frat in the first place, to help each other.

Then maybe someone starts cheating on exams - stealing the answer key, passing it around. The brothers should stop that immediately and kick that guy out. But, sometimes it doesnt happen, sometimes they think the ends justify the means, and they work together.

Etc, etc.

If the brothers get arrogant and think that what they have is too good for any old regular person, the group can get twisted and think that they can get away with hazing someone, because they're not in my group, and hahahaha they want to join, wow they're not worthy, they won't be worthy unless they can prove they can deal with my bullshit.

BUT. back to the original point of the backpack load sharing thing. That's not hazing. Because the ideal frat is SUPPOSED to be a team effort. It's supposed to be one unit working together to accomplish greatness. The pledging process is supposed to weed out people who won't contribute, people who won't actually put in the work for the group when they mooch off of it's success. So, sharing a load of encyclopaedias is a physical metaphor for that. The pledge group is supposed to demonstrate their ability to work together to accomplish a goal - not letting the encylopaedias hit the ground. The military does similar things, because the goal is a unit.

Things like paddling don't really accomplish anything. They just prove that you can put up with bullshit and don't have the ability to think on your own.