This has been my observation as well, having attending such events off and on over the years as I moved between cities. The more extroverted people connected with each other and were never to be seen again after one or two events, leaving the shy/awkward around as regulars.
In bigger cities, though, there's a constant influx of new arrivals so it's not so bad.
In bigger cities, though, there's a constant influx of new arrivals so it's not so bad.