Would you support experiments on live humans?
We can arbitrarily draw the line between human and the non human.
Giving up any pretence that there’s a rational argument to defend and not just something arbitrary only justifies the criticism.
I mean if the concern if experiments on live humans then why can't one just specifically address the concern and draw the line ?
If you think it's not arbitrary then you are free to make that case, and then I or someone else will point out flaws like the special pleading that is already glaring. Peter Singer's work on speciesism is a good place to find out the obstacles you will have in constructing a non-fallacious, non-arbitrary argument.
> Animal rights are a purely emotional impulse
That would be like saying you're going on holiday but there's no need to take account of the climate or weather.
Humans have emotions, therefore they are a consideration. To ignore emotions is not rational at all.
> We know that by training other humans not to harm humans we reduce the likelihood that we will face hardship. There is no reason to include animals in this system other than that some people feel more sympathy for them.
I, and many others throughout history would disagree with this assertion. As Tolstoy wrote: “As long as there are slaughter houses there will always be battlefields.” Psychopaths that hunt humans are well known for beginning on small animals and working their way up.
You may say that not all of society are psychopathic, but then we could ask if you would want to live somewhere where animal rights are strong, like the UK, or China, where they aren't even part of public consciousness.
If the powerful treat the less powerful badly, then I'd say it's naive to rely on their making the same arbitrary distinction between humans and other animals as you're relying on here.
Edit: missed out that very important word!