I don't believe there is anything faulty about what I wrote, I was simply trying to pinpoint exactly what you mean by equality. We have both explicit (the law) and implicit (mores) social contracts at work in our society. It is my contention that the serial killer is essentially at the mercy of his genetics and upbringing, and despite being cognizant of the nature of his crimes, he still cannot help himself. There is an absolute absence of true equality in our society, and when we try to construct any system which seeks to act upon one individual while not acting upon another (regardless of criteria) we are establishing an unequal system. By your logic, a law whereby sodomy was made illegal, so long as every individual who practiced sodomy faced the same punishment, would be considered a fair law. However, just as serial killers are more driven to murder, male homosexuals are more driven to commit sodomy and are therefore more susceptible to suffering the consequences of said law. This is essentially unfair.
You seem to be in support of a legal system which is at its heart unfair, but opposed to a moral system on the basis that it is unfair. Productive, intelligent, rich, powerful people are seen as better because by many standards they are better. They are better at imparting their wills upon the environment, getting things done, and affecting society in ways which might be better for everyone (including the less intelligent, less productive, poor people). Just like with laws: You do X, you receive punishment Y; this social system provides positive and negative consequences when certain criteria are met: You achieve success, you are treated better. And, just as with laws, some people are more naturally equipped to 'meet' certain criteria.
Does this make sense?