This sort of personalization is no different than using a user's click history to determine whether he means cycling or motorcycling when he searches for "biking". It's no different than using history to determine whether someone is looking for a television schedule or coding help when he searches for "programming".
One person's "confirmation bias" is another person's "relevance". Increasing relevance to the user will naturally result in confirming their biases, because there's (probably) no programmatic way to discern contentious subjects in which confirmation bias is applicable from non-contentious subjects where it's not.
The only "shame" I see here is people who ascribe some sort of devious intention to what's clearly the natural result of trying to solve the most important problem in search.
One person's "confirmation bias" is another person's "relevance". Increasing relevance to the user will naturally result in confirming their biases, because there's (probably) no programmatic way to discern contentious subjects in which confirmation bias is applicable from non-contentious subjects where it's not.
The only "shame" I see here is people who ascribe some sort of devious intention to what's clearly the natural result of trying to solve the most important problem in search.