Competitions in Utah are virtually only affiliated with NDCA regulations. The NDCA rulebook states
"2.Novice. Open Syllabus. It is recommended that “Novice” competitions generally be restricted to two (2) of the allowed dances for each style.
3. Pre-Championship. Open Syllabus. It is recommended that “Pre-Championship” competitions generally be restricted to three or four (3-4) of the allowed dances for each style.
4. Open Amateur. Open syllabus. All of the dances in each style must be done in this category in all rounds, and in the order prescribed." (Article X Section B, #2-4).
This is usually in response to the heavy hand of BYU's dancesport factory. What non-Utah dancers don't realize is that a lot of dancers switch partners with the end of an academic calendar year. Some graduate and there are always new bottom feeders into the Novice/PC ranks. With this heavy turnover in partnerships and a focus of preparing for the only two major competitions in Utah (BYU Dancesport in November and NDCA Nationals in March), most inexperienced dancers can only prepare two to three dances in a semester.
In response to the OP's question: As recent as two years ago, Pre Champ competition in Utah from January to April always had four dances. As long as I've been in Utah (ten years), novice has only ever had two dances (waltz and quickstep).
Skilled Utah dancers seem to specialize or do ten dance. Many also do American Smooth (BYU is, in my opinion, the training ground for the best new rising star pro smooth dancers. If Travis and Jaimee Tuft win RS Pro at USDC, that will mark the fourth time in five years that the RS Pro Champions have a BYU connection). But I digress...
Utah also has a wide network of local one day competitions hosted by the area high schools. These competitions generally mimic the entry requirements of BYU because they all feed into BYU's NDCA-sanctioned competitions.
So consider the following:
1) The average partnership lifespan in Utah is probably six to eight months. While many couples have danced together for years, the majority of open competitors don't make it to the one year mark. Dancers then have to start over with a new partner, master technique, get new choreography, and keep up with their school work. That's really hard to do in ten weeks.
2) The OP suggests that Utah doesn't emphasize certain dances, such as tango. However, much of the BYU-organized competitions actually consist of one-dance syllabus events for each style and category. A beginning standard dancer learns their first tango steps and competes after four months of dancing, sometimes less. That is true for both American and International styles. And, more specifically, tango is always included as a dance in the pre-champ category in Utah.
3) As far as the Viennese Waltz and the Jive, I think you'd be hard-pressed to find either of those dances competed at a pre-champ level anywhere (I have seen some jive though at other comps). So the assertion that Utah values some dances over others doesn't hold much weight, IMO.
4) Many of the open competitors in Utah are also on the BYU ballroom dance company or other formation teams which require significant time outside of regular partner training, further limiting their ability to learn and master multiple dances.
5) The only reason that the NDCA Nationals no longer have four dances in pre-champ is not because the organizers are trying to emphasize certain dances over others, but simply because they have added other events and only have a limited time frame in the arena. Adding in the U21 categories last year forced the organizers to clip one dance from the adult pre champ, the youth pre champ, and others, so they took out Foxtrot. They have also had to respond to a dramatic increase in the number of youth formation teams who compete at that comp. They added another day (Wednesday) to accommodate that, but the addition of other events has crowded the schedule. In short, something's gotta give...
Ideas to remedy the problem:
1. Utah could use the pre-novice category. Only problem with that is the NDCA comps don't have room in the schedule for these events AND novice AND pre champ AND Championship. And since most of the participants in the NDCA comps are local, they will train to match that schedule.
2. Utah could actually enforce age and proficiency requirements. Forcing people to move up through the ranks would open up the competitive field and thus make double entries in novice and pre-champ more viable for healthy competition and measuring progress.
3. Utah could finally organize a viable USA Dance chapter and start a competition that competes with NDCA. But given the current political climate between those two organizations and the fact that Lee Wakefield is the Ballroom Director for the NDCA I don't see this happening soon.
4. Someone in Utah could organize another NDCA comp. Heaven forbid that we organize the Utah Star Ball, encourage professional development, training, and competition and create a viable pro/am climate in this state....Another comp could offer additional dances that the OP is seeking.
I could go on and on, but the bottom line is that Utah organizers aren't promoting certain dances more than others but they are promoting certain dancers more than others. The NDCA comps in Utah are organized by BYU. Most of the competitors in open categories at these comps are BYU students. BYU students and faculty have significant constraints on their time and face heavy turnover. And since Utah doesn't have USA Dance or professional competitions, very few amateur dancers are going to dish out the $$$ to go to those comps unless they are already competing in the full championship category, in which case the OP's point is moot.
PHEW. I think I am done now. If you ever want to talk about Utah dance culture, feel free to PM me.