Like, it's not like AC is a competitive game in any way. If someone happens to want to "manipulate time" or whatever, then what the hell is the problem?
the proliferation of modding DS/3DS did weird things to the experience of playing AC online with randoms through the internet
my assumption is that if two players went offline on their individual switch consoles, they could visit one another's towns through local multiplayer
so one player goes in, drops valuable or rare stuff, and then reloads their cloud save
now they've got two, and they could multiply that further
they could force an internet connection when playing local MP to prevent this but that'd be kind of wack too
and then you end up with a situation where the people who were willing to dupe sort of just dominate the trading economy online and dictate how it plays out
but i'm not arguing that duping or manipulating backup saves in AC is the worst thing in the world that could happen, it just makes sense that they'd take measures to prevent it
they really ought to take measures to protect people's save data too, though. there's probably ways to protect people's towns and save data without enabling exploits.