I am not an expert on religion, but here is my understanding -
Protection of cow is a cultural practice that has taken on a religious dimension. Nothing unusual in that. In societies where religions originate, culture and religion has always been mixed. I don't think that in Hindu religion any one cow was revered which became the symbol for all cows. Interestingly there is a holy bull - Nandi, but there is no restriction on slaughter of bulls. This may indicate that there are multiple influences on religion. Some coming from mythology, some from practices - such as not killing cows because they will produce milk and offsprings. You can have one bull impregnating multiple cows, so bulls weren't that prized. Also note that the traditional cow owning communities are also politically powerful in India - Yadavs, Jats, Gujjars, Reddys, Gowdas etc and have been over centuries. If they frowned upon cow slaughter, rest of the population would follow suit. An Indian would know that cases of cow vigilantism also happen in areas where these groups are dominant.
Hinduism was competing with Buddhism and Jainism, both of which frowned upon meat eating. The priestly class in both Jainism and Buddhism had turned vegetarian and propagated the idea that humans did not need to eat meat to live healthy, and that other living beings had a right to live too. This idea was catching up then (as it is catching up again now) and the meat eating Hindu clergy found this to be disadvantageous. To keep up, they shunned meat too (and/or probably were genuinely converted to the idea of vegetarianism). Over generations, vegetarians started abhorring meat. This is natural. Once you give up eating meat, you don't want to handle it either, or even look at it. It even becomes dirty for you.
Now combine this with the existing taboo on killing cows. It becomes double sacrilege if you are a vegetarian. I have a good friend from the Gowda community, a well to do and influential man. He is staunchly opposed to cow slaughter. He says his reason is not related to religion, but the fact that the cow provides us so much that it is wrong to kill it. He has a goshala where he takes care of end-of-life cows, but safe to say, it is not enough, and not every cow owner can afford this system. Should I ridicule him for his affection towards his cows? I don't. He has every right to feel what he does. It is not a bad thought. No one is getting hurt or offended by his affection. He is also not forcing others not to sell their cows to butchers.
I understand this is not the case everywhere, and most of the people opposing cow slaughter don't even own cows. But we cannot stop someone who consumes milk from feeling grateful to the cow and not wanting it killed. This is the first step that needs addressing for a non Hindu when they see what they consider an irrational obsession with cow. What is the value of the goat that muslims sacrifice on Eid? Are you not supposed to rear it for some time, develop affection to it and then slaughter it, as a symbol that you have sacrificed something dear to you? In the case of Hindus, we don't want to sacrifice something dear to us. Different perspectives, but entirely believable. The second step is to see it as a religious belief that needs to be respected. Matters of faith cannot be argued upon using logic. Otherwise many holes can be poked into many religious beliefs of any religion.
I eat beef, not to prove a point, but because it is available, legally. It is most likely bull or oxen or buffalo, I don't know. I cannot differentiate either. If it was not available, I wouldn't raise a hue and cry about it. I however do have a beef with (pun intended) Hindus not knowing or bothering what happens to the cows, whose milk they consume all their life in some form or the other. I have written about this multiple times earlier on PDF and other social media platforms, but in short - if you want cow slaughter to stop, the dairy industry needs to be abolished. Now tell that to the Brahmins and Banias who have near monopoly on sweet shops and take pride on their 'shuddh milk products'. I don't drink milk because I can't digest it anymore. There is nothing wrong with my health. We are the only species who continue drinking milk after our initial years. It is not necessary. I am strongly in favour of abolition of this industry.
