1. India equates cow to humans and the punishment for killing a cow is the same as killing a human.
Intelligence is not the only criteria for respect in Hinduism, its measured by your contribution to society.
Since a cow is a contributing member of Indian society, Hindu ethics and morality dictates that it be given the protection of that same society just like any human being.
2. Indian value system is to minimize harm to other living creatures while consuming food. Fruits and vegetables are part of a symbiotic system where we consume their flesh and their seeds finds their way into the ground for germination. The relations is Symbiotic, and not parasitic.
In fact for those who practice even a stricter code (Jains, brahmins,,etc), even roots of plants are forbidden since eating them would kill the whole plant and make humans a parasite. E.g. onions, potato etc.
3. Breathing is not voluntary, and many bacteria's continue to live in our guts, nostrils etc. However, many Jains and brahmin take precautions to even prevent that harm.
4. Consuming flesh of dead animals is not the same as sacrifice.
If it is then this sacrifice during Eid has no special significance since even McDonalds does "sacrifice" on a daily basis.
5. Even among christians, the concept of animal sacrifice has been eliminated on moral and ethical grounds. Same with Hindus who eliminated this practice over 2000 years ago.
6. Finally, the concept of "sacrifice" is symbolic since Abraham himself substituted his child for a goat. So you can very well substitute a goat with a vegetable or a plant. That fact that you dont, points to barbaric and malefic intent.