I know that Delta own only 49% to meet international rules but ... after they bought their shares, many things changed. From a pax perspective one of the irritating ones was the website being hosted in the USA and the changes in it.
One simple example, having broken the BA + SAA hold on JNB + CPT, they then dropped CPT. With SAA imploding, this left BA a wide open target. Now they only serve it CPT the southern summer. Again, leaving BA to milk the route.
Thats life.