Regardless of your personal opinions and/or biases, it is still a political banner containing the name of a political advocacy group on a software development tool project page with what I'm sure is a very diverse set of users.

Some folks actively avoid politics, and seeing it at Go doesn't increase my confidence in the judgement of the folks leading Go.

The "you're actively with us, otherwise you're against us" mindset must learn nuance. Not everybody has to be political all of the time.