Put it this way Zod:
1. Guy discovers Bathory in the mid-80's, there was virtually nothing else at the time, the production and playing "skills" were kind of standards-setting in their own way. Guy just has to bow to Bathory, and of course still does on affective values.
2. Guy discovers Bathory today, the stuff sounds badly outdated, the singing is a joke, the tunes are straightforward, the atmosphere acknowledgeable but prehistoric compared to what other bands have achieved since then in terms of layered and immersive soundscapes. Still, those bands guy listens to bow to Bathory, so guy bows in turns to Bathory by procuration, and maybe because he manages to develop a retrospective liking based on experience and a lot of self-persuasion.
Bottom line: just wait a few decades until the new bands who will land tomorrow's musical milestones don't refer to Bathory anymore as the father of extreme metal. And even then nothing will change much. Instead of actively influencing musicians, Bathory will freeze in time as an icon of musical history, and it will be even more blasphemy to diss his music. I mean look at what Mozart means to the world, and you'll find no damn fuck to claim that his music is actually influenced by Mozart (well, maybe Morgan from Marduk, but we're talking hopeless here, ain't we?)