You may not have intended to be offensive, but your question is undoubtedly so.
Is being left-handed a mistake? Is being a woman a mistake? Is being a child a mistake? Is being a lesbian a mistake? Is being black a mistake? Is being single a mistake?
For some people currently (and definitely for many people in the past), the answer to these questions is/was undoubtedly “Yes.”
Those people are called bigots. Obviously, there’s nothing wrong with any of the intrinsic human qualities I listed above, individually and collectively. They’re what make humanity beautiful and special.
Introversion is one of those beautiful and special intrinsic qualities. Ambiversion and extroversion are as well. But only extroversion is privileged (as are right-handedness, maleness, adulthood, heterosexuality, whiteness, and marriage). You won’t be questioned or second-guessed holding any of the qualities in parentheses. But you will if you fall outside of them.
Just like you did to me and all other introverts.
Please try to do better in the future.