Why is being quiet considered a bad quality?

Communication and ertiveness (which are positive) are, in today's society, ociated with constant verbal diarrhea. So to not express one's self out loud unceasingly is to be weird, and thus shy, mute, boring, snobby, aloof, etc. I live in a similar situation and it is indeed annoying. Just let them think what they want to think. It's their loss if they're not willing to ASK you for an opinion just because you don't volunteer it readily and with no thought as they often do.