Earlier quoted context omitted.
Larry Sanger literally does not understand what the concept of bias is. He has said: "you aligned yourself with one side, against another side, in a debate. That makes you biased, not neutral." He's so unable to engage with ideas he doesn't agree with that he's conflated having a stance with "bias".
It sounds to me like you're just nitpicking his words. I can't find this quote anywhere, but he's probably saying Wikipedia is taking "stances", to use your word, on subjects where it should instead be trying harder to be neutral and provide multiple perspectives in a balanced manner. Sincerely trying to understand and convey the perspectives of two opposing sides looks vastly different from taking one side, amplifyi…
He first invents a link between a topic being "complex" with not being able to take a side. Then he conflates taking a side with "bias".
This is detached from reality. That is not nitpicking words. This is a word salad that starts with a need to dismiss a viewpoint and works backwards.
This "co-founder" was let go from Wikipedia in its first year over 20 years ago. He's had a crusade against them ever since.