Used to be Buriram was the poor cousin of Surin. Now it has had a complete reversal of status. Even the Makro in Buriram is a much better place to shop than the one in Surin. Better management, choices, pricing, resupply, etc.
Hard to justify the expense of re-opening and re-furbishing an airport for just occasional flights. There must surely be a break even point of so many flights a day. What do the staff of Air Asia/Nok and others do on the 3/4 days there are no flights, plus of course all the dozens of ground staff and control tower employees etc. The likes of you and me would of course much prefer to fly rather than sit on a bus for hours on end, but it seems to be second nature to most Thais and far far cheaper. If Surin had a benefactor, like Buriram has Newin, then maybe, just maybe!