As a former A-Lister who moved on to AS once my home base SAN became a focus city, I find it so ironic that WN loyalists now want the Government to mandate interlining. The last time I checked, the US is still a democracy, where airlines are public entities, passengers are free to choose the carrier that best suits their needs. If getting to your destination in a timely manner on a consistent basis is a priority, choose a more reliable carrier, which has negotiated interlining agreements with other carriers - instead of free bags and snacks. It was not so long ago that the big 3 (AA. DL, UA) sparred over interlining, believe it was the great recession that forced them to play nice together again.
Government in a capitalist system should be limited to defining safety regulations, assure some minimum level of competition. Policies like interlining should be defined by the free market - if important to a consumer, they will choose a carrier that offers the feature.