I would likely be just as put off by a picture of Spongebob or Goofy or Goku in a readme as Anya, fwiw.

maybe you should evaluate whether arbitrary societal norms of "professionalism" or something else are leading to you miss out on cool stuff

Wouldn’t quite go that far. I’ve only met one anime fan in my entire career.

Do you ask everyone you meet?

Then you must be old. Even in western countries Spy x Family (which the character is from) has sold millions of copies, while most people read mangas online and won't be counted. In the country I am from I frequently see people wearing merch of it, mostly because Uniqlo has had a successful line of it. And that is just one manga/anime out of hundreds of popular ones.

Using anime characters is similar to boomer nerds referencing Marvel/DC comics , Star Wars etc.