This is a textbook case of something every first-year statistics student studies: voluntary response bias. https://en.wikipedia.org/wiki/Response_bias https://

This is a textbook case of something every first-year statistics student studies: voluntary response bias. https://en.wikipedia.org/wiki/Response_bias https://en.wikipedia.org/wiki/Response_bias If I remember, things like these tend to draw out extremes, but the missing middle tends to be more moderate.