You need to understand the historical context of hazing prospective members of fraternal organizations at the time this cartoon was made… There were catalog houses that specialized in producing devices for “hilariously” abusing the neophytes; I think BoingBoing has previously posted references to some of them. Some of what Bimbo is subjected to is exaggerated from the sort of trials those were used in.
Typically, of course, this was inflicted on people who DID want to be members, rather than strangers off the street who weren’t interested. That’s part of the gag. Such as it is.
Of course as with any kind of hazing or serial bullying, those who survived it tended to feel that “if I could take it, they can take it” and pass it along to the next set of neos. It took a lot of courage for someone to stand up and say “I stood it, so you can’t call me a coward – but it was still wrong and needs to be abolished.”
This is mostly gone from modern fraternal organizations – but for some reason, people keep trying to reintroduce it, so keeping it out requires active policing. I’m associated with one such; I’ve heard a few stories about rogue chapters that have had to be shut down completely because that was the only way to reliably break the cycle.