It's all quite simple.
I was personally told by three separate VP's at DAL about seven years ago, that....'we will never again purchase a four engine type and, if we buy or merge with another carrier that has four engine types, they will be sold as rapidly as possible, without disrupting scheduled service
And, we will never be in the freight business again.'
Which belies your attempted point that the airplanes were retired for their poor condition. They were not, and they are not in poor condition. Again, I've flown them recently. You?
Now, as for Kalitta, we all remember this...
Also irrelevant to the matter at hand. Given that your assertions are without merit, perhaps you'll simply drop it, and go back to carrying on about the L-1011.