So as someone who lives this each and every day, I applaud how accurate your assessment is here.
Yes, Bumfuk, Missouri used to have a 727 that stopped there on its way between DFW and ORD - and unfortunately the youngest member of their airport governing Board was on the Board then too. They settled for regional jets, though like you say, they b* and moaned about that. Now regionals can't serve their market and they look to us (air service consultants) to replace that service - but with jets, none of that turboprop nonsense.
Yes, all of these markets think they can sustain mainline narrowbody service 3x day.
"Did you tell them about all of the breweries we've opened recently?" is a question I legitimately get from communities when recapping calls I've had with airline network planners.
"You get us the flight and we'll find you the passengers." Another statement small community leaders like to put out there during our airline meetings - and one that makes me sink into my chair.
It's a bad time for small markets for sure. I work with EAS markets, and regional carriers are struggling to serve even those - the ones with a federal revenue guarantee tied to them!
I could say more, but I literally have to go back to writing one of the grant applications mentioned in the article.