Those were hardly mainstream either. SRV was never topping the charts. The fear-mongering behind metal was mainstream 80s though.
SRV was pretty big man. Maybe not Madonna big but his albums sold like crazy and mtv played his videos constantly. I’m pretty sure his first album has even gone Platinum by the time his second one has even come out. I mean he wasn’t the biggest thing in the world but he was a big deal. By the time he died he was approaching Eric Clapton status.