I never said anything about the only people in urban areas being poor or non-white.
No, you are claiming that the people who benefit from rural airport service are all wealthy, white people. Your anecdote aside, I don't see why that would be true of rural airports but not large urban airports (that in fact do get a huge amount of federal subsidies quite apart from security and air traffic controllers), unless you believe that only wealthy white people live in places like Greenville, MS or rural Alaska (Martha's Vineyard doesn't have EAS service btw).
I'm fine with not worth spending federal tax money on air travel to places where the roads are hard to get through part of the year or are several hours away from an interstate much less a major airport, but I think calling it a frivolity is a bit much.
What proportion of the population in Greenville, Mississippi has actually used an EAS route? What proportion of the population in Greenville, Mississippi goes any further away than Memphis or New Orleans on a semi-regular basis? The handful of people there who do jet-set off to far-flung locales are probably confined to the local politicians and a handful of wealthy business and property owners. And there's nothing stopping those people from either hiring a private plane for themselves or getting in their car and driving to Memphis to catch a flight out of there.
