Oh let's be honest. NCSloth just lost interest in dealing with the west, including Paragon employees. So they pulled the plug in the corporate version of a temper tantrum and went back home. And now they're startled to realize they left a big ol' PR mess behind. Like when some strip-mining company leaves a toxic mess for some small local community to clean up.
It's just corporate callousness. They're so far above the "l'il people" that we don't even exist to 'em.
As for selling CoH, I'm sure if anyone ponied up some outrageous amount of cash, say whatever they paid for CoH in the first place, they'd sell. Only that's unrealistic. The game is older, the great mass of MMO players moved on. So they just close it down and bury the code on some stick in a vault, where it never gets seen again.