someone told me I should change. why does society have a bias against introverts?

to begin with, I’m an introvert. I value my time alone, and I prefer having few, dependable friends. I’ve complained to him awhile ago about how lonely it can get sometimes. however, I’ve always accepted that this is who I am. I don’t have to go out of my way to parties or to form deeper friendships. I’ve always thought that was it was OK for me to be a little more reserved and shy than communicative and assertive. I’m not a bad person or anything. I think I get along pretty well with a lot of people. I just don’t know them on a personal level. I feel uncomfortable stepping out there. I’ve always been “introverted” since I was a kid anyway, and I never seemed to have a huge problem with it..

anyway, that’s the background.

a little while ago, someone I care a lot about told me to basically change. he made it seem like keeping to myself was a bad thing. now I’m doubting my acceptance to who I am. Is being introverted really that bad? As he kept talking about how I should “live more” socially, such as parties, (which isn’t in my nature..) I kept thinking that something was wrong with me, and I never realized it. unlike me, he’s an outgoing person who engages outside. I do go outside at times (not as much as him obviously), but I don’t do the things he does (eg. partying). what he said pained my heart for some reason. I feel looked down upon and separated from society as an introvert. is it really something I should feel ashamed about? is he right that I need to change instantly?