Jim Morrison, John Fogerty, and ... that's all I got.
I can name you all four Beatles though. And Pete Best.
I don't think it's THAT he claimed to not know any of the Beatles, but moreso HOW he claimed to not know any of the Beatles. Granted, the story doesn't elaborate on that so I'm speculating, but my hunch is that, like @Snowfly said, he probably comes across as sounding a little "proud" that he doesn't know any of their names. Probably thinking its cool not to know. And that, combined with the fact that so many people are predisposed to dislike him makes it easy to pick on him for this.
Picture this: Somebody asks Rory if he ever listened to the Doors or CCR and he could just smile his smile and say, "Sorry, I don't know who they are." Or laugh an embarrased laugh with no answer because he recognizes by the nature of the question that he probably should know. People will [continue to] think he's just young and charming.
Somebody asking Sergio the same question a few years ago (I'm thinking first US Open at Bethpage era - so maybe a better choice would be Billy Joel or Bruce Springsteen) and he gives a flat, unapologetic "no" or "next question" ... he's going to get roasted for that.
It has nothing to do with the music, it's the attitude and the already formed opinions.
Not saying the opinions aren't justified, because Lord knows that both Bubba and Sergio have earned their wrath, just saying that I believe that's what's driving the negative pub, not the fact that he claims to not know any of the Beatles names. And, like Sergio, I don't claim to try and make excuses for their sometimes shitty behavior but I also don't give them too much crap for it. They are both the same kind of passionate people who share their emotions with the world. Even the bad ones. There are, to put it as plainly as possible ... real.
Part of me wants to like Bubba but his constant spastic behavior, whining, and rudeness just makes it impossible. I don't root against him, but I don't think I can ever route for him.
He keeps on spouting BS about this being his year of "rejoicing" but treating fans like an inconvenience, his caddy like garbage, and the birthplace of golf like a hellhole doesn't really seem like rejoicing to me.