And maybe they would were they not being used for flights to places like HKG, TLV, PVG, etc. Besides, if it meant the difference between two flights or four flights, many customers would prefer the four flights with some on smaller planes, just like they prefer ERJ frequencies over 1x daily 73s.

Having a higher LF on a smaller plane year-round is generally better than having a larger plane full sometimes and empty others. Combined with considerations like the costs of acquiring the aircraft in question, it seems that operating the 752s to destinations they can reach makes a lot of sense for CO.