I get the sentiment of what you're saying, but I don’t think that’s totally fair to the parent.
Biases aren’t automatically "bad" or "failings". they’re akin to heuristics, and it’s practically impossible to eliminate them entirely. For example, we’re all here talking about how we should treat Wikipedia with skepticism. That's a sort of "neutral" bias that doesn't conjure a strong emotion, and is perhaps more acceptable for it, and probably leads to better informational hygiene overall.
In fact, the claim that “bias can be avoided and should be absolutely”, that is implicit in your resposne reflects a bias of its own: a bias toward moral or intellectual purity, as if the parent recognizing bias is equivalent to endorsing it. I get that this is a pedantic point to make but to come at the parent with such vigour for being realistic, again seems a bit unfair
In fact, the claim that “bias can be avoided and should be absolutely”, that is implicit in your resposne reflects a bias of its own: a bias toward moral or intellectual purity, as if the parent recognizing bias is equivalent to endorsing it. I get that this is a pedantic point to make but to come at the parent with such vigour for being realistic, again seems a bit unfair