There are a number of stumbling blocks to obtaining widespread appeal. One is availability of live performances.
Drum corps is most compelling when viewed live and in person. However, the drum corps performance season is short. In addition, a great many localities are not within one hour of a single drum corps show. Moreover, many localities that host a show will host only one show the entire summer. Other forms of live music do not have this problem.
An orchestra, for example, tends to focus on the single community (some tour, of course). It is of the community in one significant sense or another, it markets to that community intensively, and it provides multiple performances that cover a majority of the calendar year.
Other forms of commercial music are even more ubiquitous as the live entertainment in eating and drinking establishments.
So, how can drum corps overcome this hurdle? Given current technology, I'm at a loss to come up with a solution.
The good news is that technology will make distributing the product in real time increasingly easy.