We used to have this profession that I'm not sure exists any more. It was called "critic."
What a critic was, basically, was someone who wrote well enough that a media outlet paid them to offer their opinions on a subject to the readers or viewers. We still have those, I guess, often called "pundits" in the world of news-o-tainment (and at this point, their opinions are often not their own), but the playing field has changed dramatically with the mighty hordes of opinion-offerers that rampage across the internet.
One used to consider the most prominent critics experts in their field -- a movie critic knew movies, a literary critic knew books. And while they had insights, they often had so overwhelmed their poor brains with so much material on a subject that they had killed their ability to feel the pure joy of encountering a thing with the pure joy of the innocent.
Rob Nunn's "Interesting Though Elementary" blog considered Sherlockian critics in its latest offering, as Rob has been reading through the wealth of past Sherlockiana and running into those who didn't like Basil Rathbone's Sherlock Holmes movies or Jeremy Brett as a TV Sherlock. "So even though some things are remembered fondly, if you look close enough, there are critics in the weeds."
At which point, I, someone local media has deemed "a Sherlock Holmes expert" on more than one occasion, grumbles quietly, "I still don't like Jeremy Brett, nor remember him fondly." Because I am not a proper critic, I am a fan.
Sherlockians know a lot about Sherlock Holmes. We have a deep-seated idea of who Sherlock Holmes is, and what makes a good Sherlock Holmes . . . to us. We can be quirky. Personally, I think Will Ferrell's Holmes was a lot more interesting than Jeremy Brett's @##$@# @#$*@#$$* version. Yeah, those aren't all cuss words, but I'm sparing you that, because I'm not a proper critic.
"A proper critic" implies that there are experts in the field who can pass an objective and true judgment of a performance, but do they really exist? The way you become an expert is by loving something, being a fan of that thing, but no one becomes a fan of a thing because they love every incarnation of it. Usually there is the one triggering version that sets a fan on their course to expertise, even if it is the mental image that Conan Doyle's words conjured in their brain.
When the mass of fans for Benedict Cumberbath's Holmes rose up a decade ago, I think we saw an example of the best critic we have -- the innocent who comes upon a thing for the first time and goes, "WOW, THIS IS GREAT!!!" The old Rathbone and Brett fans of established clubs were not alway quick to sign on, but Cumberbatch was producing the fans of the future, a necessary part of the cycle. As Cumberbatch fever has tempered, Brett fans reclaimed some ground, gaining converts among the fresh faces, just as Rathbone fans did when Brett came on strong, and the cycle continues.
At some point one starts to see the generational cycles, and finer points become clear. We don't have the records of Basil Rathbone fans getting pissed off when he left the Victorian era and started fighting Nazis the way we have living memory of Benedict Cumberbatch and the dread season four. (Of course, it was WWII, and everybody who wasn't a Nazi pretty much hated Nazis, so it was probably less troubling to Rathbone fans of the day.) And the meaning of words themselves, like "critic" starts to shift more toward one aspect of meaning than another, as the era of the professional critic fades.
We will always have "experts" who are fans at their core, biassed as can be but covering it up with writing skills and knowledge of the past (and . . . sometimes . . . claims of being an elevated "afficionado" or the like), and there are going to be those who viciously go after the new Sherlock on the block for being different from their most beloved. (Or Watson, or the Irregulars, as we saw in the case of The Irregulars. Enola is lucky enough to be new and not have previous fans.) But it's the love of the first-timers that buoys any Sherlock to the top and gives us fresh Sherlockians.
And you have to love that. Who needs critics?