After some changes in wattpad before a lot of people migrated to ao3. Such a big upscale in popularity of ao3 caused a very infamous look to it as people had no manners and caused issues. That might've been the reason why they call it a "white issue" tho for me its really racist as ao3 is a site for everyone no matter who they are and it being down is great pain for every user.
To add to what you said before, people telling others to "read a book" IS really stupid because ao3 is mostly made up of fanfics, crossovers and precisely tagged works just to someone's liking, not a NEW work of which someone doesn't know anything.

I'm not a big AO3 reader, Ive only ever used it to read phainaxa fanfiction but even then that was very rare. My girlfriend reads a lot of AO3 because she's has a lot of ships she enjoys, so I actually learnt about the whole AO3 shutdown from her. She's disappointed because no more late night reading for now lol. That said I don't think it's wrong for people to be upset AO3 is down, telling people to go read a book is stupid because a lot of the things in AO3 are from said books. A lot of these people who are 'crashing out' or whatever you wanna call it are probably joking. Not just that but when I did my once in a month scroll on tiktok the comments on these videos actually piss me off. 'this is such a white issue' what is that supposed to mean?? Do people think white people are the only ones reading AO3 or something? I'm Japanese and my girlfriends Korean and we both read AO3. I don't like white people that much either but I won't call everything that happens a white issue unless it actually is a white issue. I don't know, implying that poc don't read AO3 or are also upset about it is a little icky to me. I saw plenty of poc upset about it to, if your just seeing white people upset about it then that's probably your algorithm. I just know if mangago was down for 2 weeks the people here would be upset to. I mean to be honest I don't get why everyone is against AO3, did I miss something??