I do understand what you mean and agree that that's true in cases. However, I think some of that attitude comes as a backlash to the immense resistance to the very idea of non-human animals having the right to live and not be tortured solely for our benefit. They're on the front lines of what's probably a huge leap in human cultural/psychological evolution - the idea that whether we are "superior" or not, we have to live more consciously of the effects of our actions. And as we know from religious and other ideologies, that's not a mental space most people want to sit and think in, nevermind act from. We generally don't want to look at ourselves, and consider the implications of our deepest held assumptions about our own superiority.
Nicely put, and I concur.
I do think PETA sometimes (not always) alienates some people, but I think many of those are also themselves coming from a heavily anthropocentric view of the universe in the first place, usually based in religious ideologies that elevate "us" against the entire rest of existence (supremacism). A bit of humility would do humanity as a whole, and our tribal tendencies a lot of good. So, while I don't agree with everything PETA does, and there are varieties even within that group, I do understand a lot of where they're coming from. However, I am very happy to see that there are now so many options besides PETA for people who are concerned about the treatment of animals (like WSPA, SPCA and local groups all over the world).
My ripping on PETA is probably disproportionate - but it's a bit like finding out that one of your gay friends is a racist, you're a bit dissapointed and confused by the situation. Having said that, I wouldn't be Vegan if I hadn't stumbled across PETA2 (yeah, I'm that much of a sucker for free stickers) so I wouldn't write them off completely. I think it was Bob Torres who once called them a "gateway drug" into the AR scene, which sounds about right to me.