I don't know if this perspective will help but I can relate to your wife.I don't like living in Germany and I am quite scared of Germans. But I kinda have to at the moment and I'm making my peace with it. But getting angry about it and frustrated about it and ranting about how everyone is unfriendly within the comfort of my home actually helps. Maybe that's all your wife is looking for? Just a safe space to rant. I am well aware that not all Germans are one way or another but every once in a while after a particularly humiliating interaction I feel better when my husband just listens to the fact that I am having a hard time without saying that it's not a big deal for him. I'm not accusing you of doing that, don't get me wrong. But maybe that's all it is. The power of the rant cannot be exaggerated. Especially if you're planning to live here long term, and it's her way to cope, it might be what she needs to do every once in a while. Having said that more than 2 m distance at the ATM is reasonable to ask for.