i definitely know myself that i'm less productive working from home than working on the office. the commute (or the ritual of it) and the different environment makes all the difference.
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
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.