Kantian philosophy is garbage.
Every philosophical theory has criticism. That does not make such theory "garbage." The argument that morality is subjective based on moral language faces as much criticism as any other arguments. Does that make the argument on ethical subjectivism (See Simple Subjectivism) garbage?
I feel that from the arguments you've provided for it, that there's a lot of circle jerking going on in the process. You're applying no moral rights which would then allow humans to appeal to apathy towards them (this doesn't limit that down to cruelty, that's just one example), and then turning around saying that they are a vessel and could be used as the scapegoat for apathetic actions towards another person.
Read my posts on indirect duty again: it is wrong to be cruel to animals because doing so reduces the feelings of compassion with humans. It has nothing to do with scapegoats or vessels; it's our indirect
duty. That's the basic of Kant's argument. Now, when talking about animal rights, we have Tom Reagan (not a Kantian) arguing that animal cruelty is wrong because we violate their rights, and their rights, which is equal to ours, comes from their inherent value as experiencing subjects of life (which he does not fully explain). Also, there are Kantians out there that does not fully agree with Kant. Some Kantians think animals have rights. For example, Mary Anne Warren, a Kantian, criticizes Reagan's argument on this mysterious inherent value and provides an argument that animal rights are weaker than human rights because animals are not rational, and thus these weaker animal rights require us not to be cruel to them. Weaker does not mean we're better than them. I also does not fully agree with Kant, although I agree that we are distinct from animals. I'm not just providing arguments on my side, but I'm addressing arguments from all sides.
Is this philosophy just an excuse to make humans sound superior or what?
Rationality does not make us superior to or "better" than animals; it's used to make a distinction. In fact, with rationality (intelligence and knowledge through reasoning), we are much more dangerous than animals, which would make us morally inferior to them. Rationality has nothing to do with perfectionism. Thus, we aren't better than or superior to animals; it's just that we are different from them.
I was wrong in the beginning, as language is associated with rationality in the whole concept of "reason". Language is related to reason in rationality, and we cannot share moral equality with animals because we can't reason with them (Warren's argument):
Why not extend this recognition of moral equality to other creatures, even though they cannot do the same for us? The answer is that we cannot. Because we cannot reason with non-human animals, we cannot always solve the problems which they may cause without harming them-although we are always obligated to try. We cannot negotiate a treaty with the feral cast and foxes, requiring them to stop preying on endangered native species in return for suitable concessions on our part.
We are equal to other humans, as we can reason with them to share the same moral equality (live peacefully without sexism or racism through agreement, for example). However, we can't accomplish that with animals.
Because, as I said, I've proven the ideals false (as has Soze) as to whether or not animals can make rational judgement.
You didn't prove anything. Just because some animals have a few of our traits does not make all animals on equal ground as us, or does it make them as human. They can't even reason with us. I have yet to see or read any sources showing a single animal existed on this planet that can behave, think, or perform as same as a human. Your argument, on the basis of animal rights and animals as humans, is just one of many arguments I read in my philosophy class. I've provided arguments from both sides, Kantian and utilitarian, on this issue. If you don't agree with them, fine, as I'm not expecting that.