It is indeed, sadly, "standard". That doesn't make it good.
> This instance only stands to you because it makes you uncomfortable.
It doesn't make me "uncomfortable". I think it's stupid.
> Own up to the specific reason for that instead of acting like the existence of "politics" in a general sense is somehow evil.
Politics are not evil. Including them in everything, when they don't need to be included, is just bad journalism. And by the way...I would say this if the mayor in question was on any side of the ideoligical spectrum. Would you?
Imagine if instead of NYC this was a small town, and a paper mentioned that even the mayor of the town stops in a certain store to get bagels every morning or whatever. Is that a partisan message?
At least to me that's just a human interest element. The mayor is a notable person, it suggests something about popularity and ties it to a name the reader already might know. It's the same as saying a celebrity shops there or whatever.
This case is a little different because NYC is a big city, but what's partisan about it? They don't mention his politics or views at all. He likes a sports team and he likes this shop. It's being mentioned as a human interest detail, because he's a minor celebrity with some readers. This is why it seems like you have some kind of political opinion about him - if you didn't, why would it be notably political at all?