I've had the exact same experience, only with a club I used to belong to. The club had two fields. I did 99% of my flying at one field. One day I was in the area of the other field and figured I stop by. Several guys were flying none of which I knew. I walked around and watched for 20-30 minutes and no one said a word to me. Now , I realize modelers aren't known for their social skills, but at a time when many clubs are loosing members and activity is low you'd figure every spectator is potential new member.