I can't disagree more. By that same analogy, sports reporters shouldn't be allowed to comment on anything unless they've former athletes in the same field, political reporters should be politicians as well (which throws objectivity even further out the window), Warren Buffet should be pretty much the only person in the world to say something about the economy and literally nobody can say something about scientific breakthroughs.You shouldn't attempt to show the gameplay of a game if you can't play the game. It's like being a guitar player and make hundreds of mistakes while playing Stairway to heaven and then justify yourself that you don't play those songs. Either practice or let someone else more capable do it.
In truth, you shouldn't be good at a game to enjoy it or to have a good understanding of it. And as far as the later is concerned: it IS important to play a game to get to know it. Same for the music analogy you give: someone who attempts to play and fails is someone who's opinion i prefer over someone who makes their opinion by just listening to it. Denying someone an opinion about a game because they don't master it is just elitist bullshit.