That's more than a little revisionist: following the CAB's demand for a joint international-class airport (Dallas refused to use GSW, and DAL had gotten way too small for the traffic, and its runways too small for international jets), Dallas, Fort Worth, and the existing airlines signed an agreement to phase out cross-state operations at local airports and move them all to DFW. When DFW opened, all the airlines moved their non-local operations there per the agreement.
Except Southwest, who'd been created after the agreement, decided they were not bound by it, and enjoyed a now empty and easily accessible airport. And since Southwest's operations were initially intrastate, they didn't fall under CAB jurisdiction, which was the reason for DFW existing in the first place.
The Airline Deregulation Act of 1978 then meant Southwest was able to expand to interstate traffic without being restrictible by a dying CAB.
Wright was passed to protect an airport which CAB had all but forced on the area (though to be fair CAB was paying for airports, which was why they wanted them regrouped). Plus bankrupting DFW would have completely broken DAL and aviation to the region.
FWIW I do agree this was ultimately a good thing in the end though. It would not have been good for DFW airport to fail, and the region definitely did need a larger airport.
It seems like we do agree with this line though:
> nobody would have bothered going out there if they weren't forced to by federal law.
And sure, IAH is the bigger international airport in Houston, but it also carries an absolutely massive amount of domestic travel as well. My comment was about having an airport be almost exclusively international travel with few domestic connections.