But they do exist. We can’t instantly change that. And some will be used for meat, we also can’t change that. So we start by trying to make more intelligent decisions, reducing societies exploitation of meat animals, and helping people understand why this is good.
Exactly this. If our choices are keeping our personal moral purity or reducing harm to minimize animal suffering and destruction of nature, I obviously choose the latter. Who cares about what's wrong or right over trying to actively stop this ecological disaster we're doing? Eating meat is socially acceptable right now, do we like it or not. Getting people to side against that is an uphill battle that won't be won by being actively hostile about it.
Of course we have responsibilities; but those are set by us - if I say something is terrible, that too must come from the perspective of human morality, since good and evil are human concepts as well. These things don't exist in nature, but we do. It is completely arrogant of us to think we'd have some sort of privilege to see ourselves separate from nature, or to know what is best for other beings, just because we are capable of what we call morality. We can live by our values and by our responsibilities, but thinking that having those somehow gives us rights over nature or more value than animals, is what has basically led to this twisted system in the first place.
On rape I somewhat disagree; it is not a necessary part of animal agriculture - but it sure as hell is a part of our industrial farming, part of the torture we're doing. And we do have sex with each other all the time just like animals, otherwise humans wouldn't exist. Or are you talking about bestiality? That is usually an abnormality among mammals in general, so that can be used to support the argument that what we're doing and allowing to happen is terrible.