Officials also expressed concerns that the site was making course evaluation information available to individuals not authorized to view the information. Sounds like they have perfectly valid concerns, actually. When it comes to protecting restricted (and potentially rather damaging information) -- which also happens to be the University's property, anyway -- it's generally prudent to suppress the source, and ask que…
Requiring these credentials seems like a perfectly legitimate way to protect this information. Later in the article it mentions other reasons that were more likely to have contributed to the decision that they made.