I have no problems with Aus and all I have some of my own as well

but if its being used to justify/sugarcoat Incest, phedophillia, ships, real people, or victims x rapist/killer/ etc, there's going to be issues.

If you need to fucking use an au to protect/cover your ship there's something wrong with it. Plus the "Its my au" excuse is real old.

I personally hate the  main gacha fnaf au/story of fnaf, simply because it changes the entire  canon fnaf story  so their ships could exist.

Like remnant doesn't exist in gacha, Glitchtrap is responsible for William killing, they come back after fnaf6 to previous forms and live in their house happily again,

it doesn't put focus on other non Afton characters, the family is absolutely flawless/perfect, there's a fucking soft universe where certain "soft characters" shouldn't exist, The Aftons never leave the house so the story is just remaining in one spot, 

Somehow William and Clara's families are alive and youngish looking, Chris, Elizabeth, Charlie, and Michael all have future children, the nightmares still somehow exist despite they're not real/physical creatures who somehow can make children with a child, Ennard can somehow make kids despite being a mash of both genders and has "the parts do it",

Elizabeth is obsessed to ice cream despite its the reason why she was captured and died in the first place, Somehow Charlie who's still a baby in diapers,/preschooler, using sippie cups/baby bottles, and is only 3 is dating Elizabeth a kindergartner who's likely 5-6 years old