You're the one putting forth the idea that if you are able to defeat somebody you're moral superior.
Of course the Dr. Doom/Spider-man comparison doesn't work either as Doom had to defeat Mephisto to get what he wanted while Spider-man was given a deal to get what he wanted and he and Mary Jane Both agreed to it.
If you want to start arguing somebody is morally superior because they beat somebody else, keep in mind that Thanos conned Mephisto while one story arc had Mephisto claims the souls of Invisible Woman, Jean Grey, and Rogue? Is Thanos the morally superior character?