Personally I have never been to the US, this is what I have been told by Daly - might be his impression is some leftover from his teenage years (he must be around 40 now), say, I would expect the situation has changed with the average youngster being more online than it used to be in the 90/00s
First, I should mention that I'm older than Daly so my experiences are from an earlier time.
It also reads that he left South Carolina as soon as he graduated high school so he didn't stick around to see the people he knew continuing to discover things.
There are just way too many variables like what part of South Carolina (this is a major variable - if you were from a smaller city or town, the chances of discovering things (before the internet) were greatly lessened).
Another variable is how social he was and what his social circle was like.
In the larger cities, there can be and have been "alternative countercultures" that are often centered around music.
For a lot of people, it's just a phase, like maybe during their teenage years so they don't really do much in the way of music discovery beyond the more superficial edges, but some people in those "alternative countercultures" keep digging wider and/or deeper - especially in independent record stores with wide and deep selections.
But mainly, it's kind of a weird question since hardly anyone anywhere in the entire country knows anything about any particular fringe musicians even if the fringe musicians were initially from the same general area as those people, although I suppose that might have changed a little with the internet.