Joo is also Finnish for "yes" or "yep", name sounds like "yes-note".
> I still don't get what the issue is...
The word "jew" (as a verb) has roots in stereotypes about Jewish people and money; it's an ethnic slur. The word "jew" (instead of "a Jew" or "Jewish") is a dismissive insult. The word itself isn't inherently offensive, but it's often weaponized in English, which is why it has a lot of historical baggage that makes people very wary when they see it.
It certainly wasn't my goto when I read it, but the fact it was for some people might suggest the developer should change it, if only for the fact that it might put off potential customers.
What a weird world we live in.