At the referenced website the rules of the contest are given:

Each rocket was to be built to 1/16th scale and use the full N impulse of 20,480Ns, the maximum allowed in California. The rockets were to be heavily clustered and at least two-stage to create impressive flights. Since the waiver only allowed 10,000 feet of altitude, and since the audience was on the ground, the rockets were designed not to fly high.

The implication is that they could have gone for considerably more altitude, but did not, so the flight did not appear as impressive as it might have.

A number of amateur organizations gave their best shots at reaching 120 kilometers during the competition for the Cheap Access To Space(CATS) Prize (the contest deadline expired last November, and I have no idea whether it will be held again.)

As yet, no one has managed to make the altitude requirement to win the prize, but it is only a matter of time. We're pedalling as fast as we can out here... ;)