Reasons to go to meetups:
After you've been attending for a while, Ideally, 3 should become #1. I'm sorry but if you cannot see the networking and social value of meetups, you're either going to the wrong one or that's just short-sighted. I know more people than I can count, including myself, who have attended meetups, met amazing friends, and gotten great jobs out of relationships even further down the road. Meetups are not always an instant-gratification thing... If you go to one or two and don't think you've learned anything, sometimes that means you need to keep going anyway and either teach others or build some new relationships.
However, if on a repeated basis you aren't able to offer any value and you receive none, stop going.