Yes, mathematicians mean something different and specific when using the word bias. The average non-expert is not misusing the word. They are using the word to express a different -- and far more popular -- meaning.
Neither is wrong, but insisting that a naming clash carries any substantive significance on an underlying issue is just silly. Similarly, insisting that nonmathematicians should stop using a certain word unless they use it how mathematicians use it is a tad ridiculous.
Of anything, it's more reasonable for mathematicians to change their language. After all, their intended meaning is far less commonly understood.