I won't get into an argument, but i'll just answer your post by something simple: how can you know that he LOVES being handled?
There are various reasons that can explain why your chameleon is reaching out your hand: his enclosure can be too small, he may have spotted another chameleon (female) in the area, he can be curious and explorer, he may be wanting more light or less light (like UV exposure), and so on. From a scientific point of view, i have seen no reason that justifies the hypothesis that "some chameleon love/like being handled".
not to sound rude, but for all you listed, isn't it at all possible that actually liking to come out of its cage may be one reason for the chameleon to want to leave its cage?
Sure UVB this and Space that, or sexual frustration and what not, but say all that was not a factor and the animal wanted out, is it so mind boggling to people that an animal may actually have some traits that *gasp and how dare he!* link it to what makes us human?
Im not saying the chameleon will know "hate" or "love" but I think that saying "its an animal, it doesn't like things" is quite the silly statement.
Your chameleon "likes" a favorite prey item, but by that same statement, a chameleon can like to stay inside of its cage or it can like to leave it.
From personal experience my Ambanja prefers to be left alone in his cage, and my Sambava tolerates coming out. I wont say like since he doesn't exactly jump on my hand and give me kisses the moment the door opens but he does come onto the hand and does not turn stress colorations and stick the infamous chameleon chin out at me. But if you do a search, its easy to find threads about chameleons that seemingly like to come out of their cage, or to hang around with their owners. Dont you think that it gives some "proof" that perhaps the animal isnt as animalistic as you believe?
Anatomically, animals have every organ Humans do. We are all made from similar Eukaryotic cell structures, we breathe the same air, metabolize the same nutritional requirements *aka the calorie*. Humans and Animals are both creatures, both of us are living breathing creatures, set on equal playing ground.
If I pinch my dog he yaps because it hurts, so he obviously feels pain, and when I come home he barks and runs to me because he is excited to see me.
This isn't so much aimed at you alone Morph as it is to the people who tend to refuse to admit that people and animals are much closer than they think. Or rather, its directed to those that use it as an excuse to abuse/neglect/mistreat/ or kill animals with no fear of consequence, after all they're just animals.