it allows people who are passionate and knowledgeable about music to play it unfettered with concerns such as audience profile / share etc.
i grew up in london in the '80s. as far as the legal stations were concerned, black / dance music didn't exist. neither radio one, radio london or capital radio played it. even if black / dance music charted, it rarely received enough airplay.
however, there was a huge pirate scene; JFM, LWR, SOLAR, KISS, to name but a few. all of these stations had dj's who knew their music, they weren't elitist, but they did specialise; for example, tim westwood had a electro / hip-hop show on LWR, weekdays between 4 - 6pm, tues - fri, and on mondays for quite a while all he would play was go-go ( think trouble funk..).
KISS, when it was pirate was truly excellent; matt black
( coldcut ) used to have a show on tuesday mornings between 01 - 03am, which i had to stay up to tape; but it was always worth it, and it was the first time i heard any hamilton bohnannon.
when i went to uni, my friends couldn't understand how a white guy knew knew so much about black music; but they'd grown up out in the provinces, where there weren't any pirates.
pirates were and still are true public service broadcasters,