This is because the city of Fargo doesn't advertise ANYTHING. I lived in Moorhead for 12 years, and vaguely remember seeing little more than a billboard for F-M Ice Sharks. The city/community doesn't embrase the Bison nearly the same way Grand Forks embraces the Sioux.
I was in awe when I came up here and saw how much support the school gets from the community. You go into Burger King on the north side (near Simplot) and all you see if Sioux stuff. Football helmets, hockey jerseys, it's everything. There is nothing like that in Fargo.
Travel around the country and who do you meet? Sioux fans. It's rare, if it ever happens, that you meet a Bison fan or see an NDSU shirt even. I see more pride coming from Sioux alumni than Bison alumni. I recently went to a concert at the Target Center and wore my Sioux jersey. I had 7 (I counted) people comment positively on the jersey (including somebody yelling 'Go Sioux' out their car window as they drove by). Rarely do I see anything Bison anywhere except Fargo.
I'm not saying this to bash the community or the school, but it's a fact of why hockey never worked in Fargo, there was no advertisment, and why hockey likely wouldn't work at NDSU, because the community and alumni don't support the school they way it's necessary.