I'm a very social guy, so it isn't an introvert thing, but I work 100% remote, I don't want to meet and be confined to 'activities' or environments where I can't be productive. If I wanted to be in an office, I have plenty of job offers to do so. If I wanted to meet my co-workers on 'activities' (like the once a year retreats with parties and trust falls and what-not) I would join the local kumbaya group.
Just thinking I have to travel for a week, away from my friends, my family my routines for someone to have face-to-face time with me that could have been done on skype/hangouts is ridiculous, and whenever I hear about yearly retreats/trips I pass on the job.