The Commissioner who said that seems to think that Guatemalans are not served in Miami by the dozen or so Spanish language stations, including 6 full coverage FMS, most of which play the same genres of music as are popular in Guatemala. That Commissioner need a bit better cultural understanding or immigrant and heritage groups... there is no such thing as a "Guatemalan format".
There are plenty of groups that never had their "own" radio service, going back to the 20's. Radio has always been called a "mass medium" because the costs of running a commercial station far exceed the potential revenue attained from niche broadcasting to the narrowest constituencies.
When such groups are large enough and have a prosperous enough community, stations take on the job of serving them. In LA, we have stations in Korean, Spanish, Mandarin Chinese, Vietnamese, and Farsi. We have extensive programming but not full stations with Tagalog, Thai, Hindi, Japanese and Armenian programming.
And today, communities that can't support a broadcast station can stream or even lease an HD channel (as is done in many markets for such programming).
I just think there’s not enough economic clout as in disposable income amongst the various minority communities or large minority owned businesses to advertise with. The raw numbers are certainly there.