I disagree, the premise is based on these aliens having the same internal makeup as humans. Man is what he is due to evolution. Maybe these creatures don't have emotions, which would make it so they wouldn't understand our emotions, or empathy. Maybe they would be hard wired to be violent and view it as a necessity. Who knows what their evolutionary history or sociology would be like. It could seem totally rediculous to us, but normal to them.
Are you attracted to monkeys with red butts? They have 99% the same type of DNA we do but their mentality is totally different on what is attractive. A Nazi concentration camp worker, Ghandi, Al Capone & mother Teresa all shared 99.9% the same DNA. this would be a totally foreign species, they probably would have 0% in common with our DNA, they wouldn't even have DNA most likely.