I don't understand why we can't, the game is in full 3D and rotating would be really helpful in some instances, especially when taking photos using the new camera app.
Yes it is disappointing that you can only switch the vertical axis. Sometimes trees block the cute villagers sitting down and I can't snap a pic - looking @ you, Audie... sitting under a tree with a donut..
The reason why is due to forced perspective, have you ever watched those boundary break episodes on animal crossing? theres a reason why we can't see certain angles lol
I get why we can't but it would have been nice when pulling all those weeds the first few days. I would have loved to have been able to make sure I wasn't missing any behind the trees!