There are a lot of people who say there's a difference between niceness and kindness. I think of niceness as to how you treat people to their face. Kindness, to me, is goodwill that goes deeper and thinks about the big picture. Kindness doesn't care much about credit.
I think most of the time, but not always, you can be both. But if you have to choose go with kind. It's stronger and more genuine.
I'd like to think that most BYU fans (and most people in general) aim for both.