The success of the show was in spite of Ralph, not because of him. The initial catalyst for it blowing up was because Ralph was able to book a bloodsports match between James Allsup and Nick Fuentes, who had been business partners until their falling out which until that point neither had addressed. The Baked Alaska Self-Immolation Experience happened the same night and Daddy Jim hopped on which led to a big boost in numbers. Jim's good will spurred a lot of traffic, but a big reason why The Killstream was so popular afterwards was because of the format.
Terrestrial talk radio is well known for having open lines and caller driven shows, even if the content of the show is boring, you can almost guarantee some random weirdo will call in and you can riff on them for content. Now imagine that, but on the Internet, in the IBS sphere. That was a huge part of the reason why The Killstream was popular, plus having interesting guests who'd take calls, plus being a more or less neutral platform for IBS and Internet drama.
Ralph as a personality had nothing to do with the Killstream's success, he just happened to be there.