Sailor Moon is a pretty poor representation of the Magical Girl genre (and a poor anime in general) TBH. It is like using something like Bakugan or Beyblade to represent sports/tournament anime instead of Gundam Build Fighters. It can be enjoyed without being familiar with genre tropes in the same way Eva can be enjoyed without being familiar with hot blooded super robot awesomeness. But you get more out of it if you've watched shows like Getter Robo and Mazinger Z before hand.
This, right here, is why people don't want to get into anime. I said I enjoyed it. I said I walked into it with almost no experience. I've claimed it's one of the best shows I've seen, let alone the best anime I've seen, and I've already disagreed with you that any sort of foreknowledge is even vaguely necessary. Your move is to completely discount my experience because I haven't seen four shows that up until now I've never even heard of. Do you need a firm grounding in L'immortal ad Vitam to enjoy Fifth Element? No. Do you need a firm grounding in Raymond Chandler books to enjoy Blade Runner? No. Do you need a firm grounding in '60s-era Soviet filmmaking to enjoy Solaris? No. Do they help? Sure. But does anyone benefit when someone says "I really liked it" only to be told "you couldn't have truly liked it, you aren't kotaku enough to truly like it"? Let it go. I'm not going to watch a half dozen Magical Girl series just to further refine my appreciation for Madoka Magica and neither is anyone else. It's just fine, as it is, streaming from Netflix, like any other show watched by any other person for any other reason in any other environment. I'm proud of you for being able to quote chapter and verse on a genre I couldn't give two shits about but your ability to quote chapter and verse on it has exactly nothing to do with whether or not I enjoy something in that genre.
Hold on. I never came close to suggesting that familiarity with magical girls is necessary to enjoy Madoka. I just disagreed with the assertion that it was best seen without any prior knowledge. I am not saying that you couldn't have truly liked it. Madoka is amazing even without knowledge of magical girls. If somebody said that you can't truly have enjoyed Evangelion without watching classic super robot shows they'd be wrong. However asserting that knowledge of super robot shows helps wouldn't be incorrect. Hence my comparison. Anime in general is pretty accessible, just like film is, but some are enjoyed more after you are familiar with the medium than before.
You still don't see the cultural elitism of your attitude. I've heard it said that to truly appreciate Star Wars II you have to immerse yourself in the Clone Wars animated series. You know what? fuck everything about that. Star Wars II was a shit movie and the 20 minutes I saw of Clone Wars convinced me that anybody who put up with the whole series is not someone whose cultural insights I trust. In fact, it alienated me further from the movie because it illustrated that the entire exercise was conceived for tastes completely alien to mine. Here I am, celebrating something that we both like. Rather than sharing in that enjoyment, you feel the need to correct me by suggesting that my enjoyment is incomplete due to my lack of exposure to a genre I don't give a shit about. There's no need to do that. We're dealing with a loose confederation of Internet nerds that might, if the stars align, manage to sit through 12 20 minute episodes of something created in a foreign language. My advice was "dive in." Yet for some reason, you feel it necessary to perform some cultural one-upmanship. Anime, in general, is not "pretty accessible." I hate most of it. I would go as far as to say that the vast majority of it is poorly created, poorly executed and a trial to get through. Madoka Magika is, in my opinion, one of the rare ones that can be enjoyed by unvernaculared gaijin. So when you imply that I need to sit through 20 hours of shit that I hate by default in order to better enjoy something that I've already stated is amazing what effect do you expect other than rankling me? Or anyone else, for that matter?
Cultural elitism is a good way to put it. Unfortunately I've found a lot of that in the anime community. Don't let it discourage you from keeping the club going. I think the club a great idea that can be soured by having these kinds of arguments instead of discussing the actual show.