I don't disagree with your points, the execution of Maxwell Lord at Wonder Woman's hands stands as a particular low-point of Dan Didio's management of the publishing line and sadly has never been an event that has been really discussed or dealt with - Wonder Woman executed a foe, and the consequences for her were minimal, indeed it didn't even trouble her, unlike Superman executing the Phantom Zone villains. Indeed even Barry Allen paid a heavy personal and professional price for his executing The Reverse-Flash. But for Wonder Woman... nothing. It stood as one of the most troubling moments in modern comics for me.
Although very much a product of the late 1980s Maxwell Lord is a character DC doesn't seem willing to let go of, a sort of modern update of the Funky Flashman/Morgan Edge opportunistic figure Maxwell Lord began life as a shady buisinessman and ran the turbulence of evolving from that to penitent sinner to underhand murderous psychopath. There was never much logic to it, just plot contrivance and another example of the dark meanness of Dan Didio's regime. So despite his uses becoming ever more limited and one-dimensional in their nature the name alone seems to be what creators keep coming back to - "Maxwell Lord" does have a pleasant ring to it after all. And it's the name and general outline of the character that still attracts creators like Patty Jenkins to pick him up and make use of him.
When done right, he is a combo of lex and Charles Xavier, so would be a very tough villain!