To make a short explanation long, back when
JLU was on TV and the episode "The Great Brain Robbery" aired, there was a mini-controversy. Flash and Luthor's minds got swapped, and at one point Tala pulled "Luthor" into a bedroom and started
playing scrabble, and some fans were sooooo offended and accused Flash of being a rapist. I believe on his old personal site, Dwayne McDuffie (RIP) addressed the issue by saying (I think) it was pretty silly to compare a real world problem with something so ridiculous from sci-fi/fantasy. I kind of feel like a similar principle should be applied to the amnesia kiss analysis. It's not really worthwhile to compare some sci-fi/fantasy nonsense to a real-world, amoral, criminal act. But if you did want to make that comparison, then I'm going to argue that changing one woman's perception of reality is probably nowhere nearly as unethical as warping reality for five billion people.
Back to
Superman Returns... probably the worst consequence of forcing it to be a
Superman II sequel is the implication that in
Superman II, Lois and Superman had an intimate relationship, shortly after Superman went on a field trip, Lois met Richard, and then got serious with Richard so soon afterward that it became plausible to all that Jason was Richard's kid. Such a rubbish implied timeline of events. And then despite insisting that it was a sequel to
Superman II, Singer further insisted that the amnesia kiss never happened (well, I guess this is a good thing for many
) even though the events of that movie are supposed to be canon. What a mess.