Well, that's just me. I'm of a benevolent temperament and like to think that, regardless of what I read about merpeople being cold, sometimes heartless creatures, that temperament would transfer no matter what form on Earth, or on other worlds, that I took.
I don't think merpeople are heartless, I think that they are animals that look a bit like people. I mean, they're just fish with human-looking front parts. I mean if an octopus see's someone drowning I don't think it's first instinct would be to go help you know?
Well, that's how my merpeople work anyways. They're just animals.