Speciesism Its merely a political argument, rather than a philosophical one. Sexism, racism, speciesism, etc. are all concepts that gained popular recognition with the invention of human rights which only emerged as a political movement due to modern technology turning the ancient practice of slavery into a nightmare on a grand scale. The average life expectancy of slaves working in the cane fields, for example, was five years, yet, they were so cheap it was still worth shipping them thousands of miles and losing up to half of them on the journey alone.
Notably, it was also money behind the adoption of human rights with the industrial north merely taking advantage of another opportunity to exploit the cotton farmers of the south. Something like 80% of Americans at the time were against freeing the slaves and when the constitution was changed to grant them equal rights as citizens the first thing those with money did was to insist it be interpreted as meaning corporations are people.
The idea that sexism, racism, etc. have been eliminated is laughable. In fact, there are an estimated 350 million slaves in the world today and even in the state of Louisiana women are still making 66c on the dollar for the same work as men. Nor has communism provided any sort of viable alternative to the problem of money and power doing all driving and, until it is resolved, progress will remain piecemeal at best.
Perhaps the best argument today against speciesism and allowing money to continue to do all the driving is the simple fact that within twenty years commercial fishing will become impossible due to their no longer being enough wild fish left in the oceans while, within fifty, every wild land animal larger than dog is projected to become either extinct or only exist in zoos. Humanity is killing itself and ranting and raving about morality or whatever has proven to be all but totally useless. What we require is something that can compete better against the mindless practice of merely following the money wherever it leads.