I'm really getting a strong hipster vibe off of you. You know, the whole "No one except me seems capable of understanding the DEPTH of this game, you're all RUINING it with your mass-produced kawaii bullshit!"
Yes, all the theories are shit and mainly thought up by 13-17 year old kids. I suggest that you just don't visit /t/, and warn interested friends against going to sites like the yume nikki wiki or mado's closet.
as for the "good" ending... shrug some people just really like happy endings, I guess? I just didn't download it. I don't care if they want their own AU version. I like the original, I play the original, end of story.
I've never played (and likely never will play) any of the fangames. But to say that they're all just "let's put a cute shemale in a bunch of creepy situations!"... well, someone could make that same claim about Yume Nikki, even though I believe they'd be dead wrong. Don't hate on the fangames just because they're fangames. Hate on the shitty ones for being shitty, sure. But seriously, novels will have fans who write shitty fanfic, manga will have fans who draw shitty fanart, and YN has fans who make shitty fangames. I'm sure there has to be one gem in the turd pile, considering that is usually what I observe about fandoms.
Creepy!Cuteness and GOOD anime openings earn points in my book, because I love dark/surreal/haunting artwork but also love girly shit, because I'm a girly girl. And really, it takes tons of dedication and talent to make a good fanmade anime OP, and I respect dedication and talent. But I understand some people don't like what I like. So, whatever floats your boat.
Really, why are you getting so butthurt over it anyway? It doesn't stop you from starting your own no-cute-allowed threads, or your own website where you discuss whatever random stuff about the game (minus stupid theories) that you want to. Or try going over the /t/ and blasting holes in the bad theories, that could be a fun enterprise. Put on your big boy undies and quite bitching about what you don't like about the fanbase. Do something to IMPROVE the fandom. Make a grade-A fangame, draw some disturbing/surreal art, or just do anything to show off how you WANT the fandom to be. And while you're at it, start your own /t/ thread where you explain to the kids WHY all their stupid "theories" are shit. I'd join you but I think it's a waste of energy to even look at that board.
Oh yeah, I forgot: Welcome to Uboachan. This is the most active board here, usually. And well, our fanbase is no more fucked up than any fanbase I've had the... pleasure?... of interacting with. Enjoy your stay.
Oh, and have some Kawaii Desu Yo Mado before you go, isn't she so Kawaii with these Kawaii Nekomimi and the kawaii ~nyan~ pose, like a kawaii little chibi neko desu yo ne? <3