When I went to Mountain View 10 years ago, the attitude was definitely pretty negative toward Timpanogos. Orem was technically our rival, but I don't know anyone who actually cared. There was, however, a very clear sense of animosity toward Timpanogos as a whole, and that was entirely based on the socioeconomic standing of the school.
I mean, maybe they were wrong about Timp, but I don't know of many lower-income areas in North Orem.