i believe it's not a problem of socialization ability, it's a matter of personality - it's just who we are. as an introvert, i'm not comfortable just striking up conversations with strangers, let alone making friends with them.
even if you don't make friends at work, being physically around people has an impact on a person. being in an office has a much higher social component than working from home.
i have my own social groups that aren't dependant on the people at work, i don't have a job to make friends but to make money