I live and run in Mexico City. And I've often asked my self this question. Granted it's a big city and we don't have many open roads like Kenya, but there are spots for some decent running. Trails in the woods at well over 10,000 feet, everything here is sort of hilly and we all pretty much live and train at altitude.
There is practically one or two races on any given weekend, I once was told that there are about 250 race in the city in a year. However you do see Kenyans taking up the big events.
But like kimani said, it's mostly made up off middle class people who do it for fun. The races are sort of expensive, but when you have to close roads in a city like this one, it won't ever be cheap. Also, I've noticed that when I'm out running in the morning (5:30 am at the latest, gotta finish early to beat traffic) there is already people walking tu bus stops or the subway to get to work, they get up even earlier just to make it to work. Running is a privilege here.
Also, you have to be REALLY into the scene to compete at track meets. Schools (college or HS) don't promote running, or any sport at all. There is no established athletics department like in the US or leagues. I'm pretty sure there are only like 5 tracks in the entire city.
Over all, there was a good thing going in the 90s but the running scene was still to small, the boom was around 10-15 years later. sure people paid attention because we're very patriotic, but I'm sure it would of been a much bigger deal if that generation was competing today. They would be stars. I also believe the torch wasn't passed to the following generations, I feel like it sort of died off. I think Barrios is pretty much the only one that anybody would recognize, and he has a very old school vibe to his training (camping for weeks at over 13,000 ft to train, he's a grinder)
Given the chance and support some decent runners would come from this area.