Running clubs are just a reflection of the racing scene. During the first running boom, it was very common for local races to have prize money. Also, there were very few runners who were training full time. It was a big deal when guys like Bill Rogers could compete professionally without working a day job. So, back then, there were a lot of runners who kept running after college either to make some cash on the weekends or with the aspiration of winning bigger races and becoming a full time pro. Naturally, these runners started running clubs to pool resources for coaching, track privileges and to do team competitions. So, back in the day, running clubs were loaded with fast guys.
Flash forward to the end of the running boom and the domination of E. Africans. Now, there are fewer and fewer local races offering prize money. The pro scene is dominated by full time runners who all congregate in a few training Meccas. Running clubs are taken over by mostly experience runners, people who make running a social activity and go to marathons more for the experience than time accomplishments. Fewer and fewer fast runners from college stick with it because races have no prize money and there is no way to get to the pro level without being in one of the few elite training groups in Boulder, Portland, Flagstaff, etc.
So, today, if you are looking to run with some folks who will challenge you, you have to go out and get your own group going. Next time you are at a race, get to know some of the folks who are a bit faster and slower than you and see whether they are interested in getting together for workouts and long runs. I am in a huge city with a bunch of running clubs and that is how the sub 3 to sub elite folks have been doing it. It is pretty rare to find more than a handful of faster runners in the local running clubs these days.