Lots of good responses here, but this post hits the nail on the head for me. I have realized over the past year that I am in the weird in-between group that is too fast for the non-competitive runners but not fast enough to catch the eye of the local sub elites. I got down to 16:30 earlier in the year before I got injured and would get a solid top 5 or top 10 at the most competitive, prize money races (except for the big races with 10,000+ runners). But the best runners were not exactly turning around at the finish asking me to join them or interested much in conversation.
I do mainly use the club runs as easy runs and also as a social activity. I understand that running is social for most people, but figured the biggest local run club would have at least a few people looking to push themselves to faster times. But they are quite rare.
I have scoured the local race results and pay attention to the people in front of me, so I know who the local fast guys are. But I have trouble getting beyond small talk with these guys and they all seem a little clubby, like I'm some upstart crashing their party. No invites to run together have been extended.
There are no other significant clubs that I'm aware of, despite the metro area having at least a couple million people. The running stores are highly interrwined with the local run club. Some of the local post-collegiates seem to run with the college teams as volunteer assistants and there seems to be some faster guys in the suburbs that know each other and chat at races. There also are a couple prominent private coaches in the area that coach some faster runners, but not willing to go that route yet. Overall, it's quite scattered and not centralized.
Anyways, based on the responses here, it seems like this is the state of the market for running clubs in most cities. The best route might be for me to start a little Facebook group that is focused on runners interested in being competitive in some category (overall, age group, gender, etc.). I have met a couple people that also have trouble finding other competitive runners. There could be a need here that needs satisfied.
On a final note, at least the local club is a good way to meet some fit young ladies.