Two main things here:
1) Again, never underestimate the placebo effect. Just as people can often be tricked into believing a modelling amp is a 'real' amp just by giving them a blind test and telling them it's the real deal, people come to believe all sorts of things about their guitars, often traits which can not actually be attributed to anything as specific as a single part or isolated alteration. Someone flips their pickup around and decides it sounds better—ignoring that they also changed strings, fixed intonation, changed the pickup height, changed the pots, changed the bridge, changed their amp, or any number of other adjustments—and suddenly they're swearing blind that flipping your pickups around is the only way to get a good sound.
2) Just because someone is popular does not mean they know more or are right. Of course it doesn't mean they are inherently wrong, either. You must take each hypothesis and theory on its own merits and not ascribe any plausibility based on notoriety. After all, Taylor Swift plays guitar and has sold many times more records than Eddie ever did, doubtlessly inspiring just as many if not more kids to pick up an instrument, yet you wouldn't take gear advice from her.
And a soft third thing: of the last 40 years, I—and I'm sure many others—would argue that Kurt Cobain has been much more influential than Eddie Van Halen. That's really another topic for another day, but while we're here, there it is.