A few things here...
Huskerzoo, I am curious as to what you (or anyone else who was there) specifically thought about the stuff that happened in the stadium that doesn't get talked about. Jump Around is what gets the publicity but the singing, the interplay between sections, the wave, etc. I've had friends come to games there from all over the country....SEC and Pac12 schools is what they know and they've scratched their heads, laughed, scratched their heads some more and still talk about it.
I don't condone the vulgarity and as others have said don't let that give you a bad impression of UW fans. Most thing the ES-FU stuff is childish and you should ignore it but it's become so ingrained in the students carrying it on year after year that it's something that won't go away so you have to live with.
With that said, I am going to call out anyone who was shocked by the ES-FU and the a-hole chants because all you had to do was just a little bit of homework. Ask on the UW boards what a game is like for a visiting fan and you would've heard about this stuff. I know I saw it on here in the past few days and maybe months ago also. You'll find threads upon threads and mentions about how this is stupid.
As UW fans a reason why we might be skeptical of the horror stories is because of the chairleg thing I referenced earlier. A few years ago there was a ridiculous claim made by a Minnesota fan about an incident where a Badger fan was harassing a guy's wife and they got into a fight. If I remember this right this Gopher fan then fought off the perp by breaking apart a chairleg in a restaurant and jamming it into the eye socket of this Badger fan. This was posted on the gopherhole and others bought it hook line and sinker. It was quickly shown to be spawned from the delusional mind and it has become a running joke. I'm pretty sure that thread is archived on Buckyville somewhere and will give you a peek into the minds who you have to deal with when you face Minnesota.
Anyway....it's unfortunate that there were some bad things that happened and I'm not going to defend the actions of a few. Crappy stuff happens everywhere. A bunch of years ago a Tennessee fan was killed in a fight in Gainesville. That's not an indictment on all Gator fans, it's just proof that there are jerks wherever you go.
I have two related theories as to why the ugliest of the ugly things might have happened. 1) Nebraska wears red. Some of these younger Badger fans might have been too lubricated or haven't been paying attention to know that this was a red team not from Columbus, Ohio. Revisit this thread after you go there to compare. You'll think your time interacting with us was mild. and 2) Nebraska is west of Wisconsin. We are new to this whole "when visitors come from the west we should get along with them" idea. It's impossible to take Minnesota seriously as they try to tell us that they have the better program because they won games during the Great Depression and the Wisconsin-Iowa thing is a result of both programs being mirror images of each other and it feels like a sibling rivalry with the brother you absolutely despise.