Jazz is an acquired taste. Certain styles are not for everyone. I am surprised that people think this type of music would go over well in the DR but it looked like the people in attendance enjoyed it. I always wondered why Sosua beach was not more active at night. It would be a great venue for live music and such.
A good question that I have wondered about for years. One reason that live music, aside from some simplified Karoake assisted version, is tough at Sosua beach is a lack of easy access to carry gear in and out. The driving reason is of course, money.
I don't think there enough people around to make it worthwhile to stay open at night. During the best of times, I was playing 4 nights a week. These days I play a gig a week, maybe two, during peak season with a trio. (Cabarete is a shell of what it used to be when I moved here, not to go too far off topic, but it is a north coast general problem)