I don't really care whether or not they are seen as people, this planet is simply one giant clusterfuck of life, divided into different organic structures perhaps, but it's all a part of the same massive clusterfuck.
I instead judge others by their actions and intentions, as those two things are always present, regardless of what species they belong to, or their level of intelligence. It's why I'm a supporter of cannibalism, and why the "Hurr durr humanz are better than everything else becuz we are" attitude I see so often can shift my mood from placid to pissed off in an incredibly short amount of time.
Also, in regards to dolphins being immoral and whatnot, let's make one thing clear:
All of nature, you, me, the plants, animals, bugs, microscopic organisms, everything, is an asshole. To varying degrees, of course. But assholes nonetheless. No creature survives on this planet without being an asshole to some extent, so pointing the finger at dolphins as a whole for doing immoral things, that humanity itself has practiced(and continues to practice) for almost its entire history, without even completely understanding the dolphins' reasoning first, only makes you an even bigger asshole then you previously were.
The important thing to remember is that, as contradictory as it sounds, just because everyone has to be an asshole sometimes, doesn't mean they can't also be generally good individuals.