I agree entirely. I am just out of undergrad, and working is a major step down socially. If it weren't for my Customer Service job I would probably interact with no more than 5 people a day (in order: my wife, boss, coworkers, wife.) (Unless you count here and Reddit.) It seems to me that he was just using his girl count as an objective measure of his social life.
The social argument was bizarre, I agree. Campuses are great places to meet new people; most of my friends agree that starting work is socially a step down. And they're at least working for large corporations with lots of people in them. Working insane hours at a startup it's unrealistic to expect your social life to be an improvement relative to *anything*.