Glenn:
I, too, lament the demise of majors in Ohio, having grown up in northeastern Ohio and attended the '73 PGA at Canterbury. Ohio had a remarkable run of majors from 1957 (it hosted both the Open and PGA that year, the PGA at Miami Valley in Dayton and the last year of match play) through '79, when Inverness last hosted the US Open. I counted nine majors plus the Ryder Cup in those 23 years, roughly one out of every 2+ years, maybe the most that any state enjoyed during that time span. It's hosted only two since then, both PGAs at Inverness.
I think two things happened. I think technology has played something of a role, along with what might be called the demands -- secondary courses, infrastructure related to big crowds, willingness of clubs to host such a big event -- of holding a major. I don't know specifically whether Ohio's classic-era clubs have been unwilling to expand/lengthen to meet today's technology demands, but many are somewhat land-locked and may simply not be willing to undertake that kind of expansion.
Secondly, both the USGA and the PGA especially made concerted efforts to change their course rotations starting @ 1980. The PGA really went after relatively new, longer courses -- Shoal Creek and Valhalla twice, Oak Tree, Kemper Lakes, Crooked Stick. That left the likes of Firestone and NCR on the sidelines. Secondly, the USGA -- notably with Shinnecock in '86 and Brookline in '88 -- made a very concerted effort (after drifting with course selection in the 1960s) to take the tournament to the country's very best, classic-era courses. And for the likes of Canterbury, my sense is that -- although it's a terrific course -- it just doesn't hold up against some of those courses as a US Open venue.
One other note: Ohio seems to have lacked a course developer (perhaps Muirfield is the exception, and Jack seems content with holding a PGA tour stop) who deliberately built a course with the aim of hosting a major. That's happened in Wisconsin, with Herb Kohler's Whistling Strats and Blackwolf Run courses, and now with the Erin Hills folks -- big places intended to host big crowds.
Having said that, Matt Ward's argument that Ohio is perhaps less deserving because of the annual tourneys at Muirfield and Firestone is, to put it mildly, quite specious. He's been arguing (with me, among others) that US Open sites ought to be determined based on merit, not geographic distribution. If an Ohio course is worthy of a major, it shouldn't have Muirfield and Firestone's events held against it.
Personally, I'd like to see the PGA return to Canterbury, with a similar attitude that the USGA took with Merion. You could play it close to 7,000 yards at a par of 70, and it's a "longer" course than perhaps the card indicates because its many doglegs force players to take something less than driver off the tee.