They always say writing an ending is the most difficult part of telling a story. As far as NK, WONK, LSONK and WOTS, I feel that they did what they could. I believe Superman wasn't as adversely affected because his own people broke the enchantment, if you understand what I mean by that. Superman had a highly romanticized view of Krypton. Conversely, he has the values of a mid-Western American, and none of that aligned with the values of Krypton and its caste system. Over time, I believe Superman felt less connected to "his own people" and more connected to earth.
That is not to say that Superman should not have had a more dramatic reaction to New Krypton's destruction (though there were moments of highly visible anger), but Earth will always be his first home. I believe JMS will begin to explore Superman's true feelings on the matter, with his new run. If you read Superman #700, you already begin to see some of the reactions of the people of Earth and Superman, in relations to the events of the past two years (real time, not comic time).