The fact that you recognize how ridiculous the analogy is suggests you know it doesn't really make the point you seem to be going for.
Sorry, but I'm not sure that's true. At the end of the day, the history of life on earth makes one very, very clear assertion: nature is bloody in tooth and claw, and almost all life lives by the taking of other lives.
I'm not going to take responsibility for that -- I'm not the author. If you think that I'm wrong, then please enlighten me.
Yes, that's true. Do you consider any and all killing to be ethically equivalent? If I kill and eat you, for example, does that have no more ethical importance than if I kill an amoeba?
There are, in fact, quite a few cannabalistic life-forms that are part of our natural world. Then again, the vast majority of species in this same world are not cannabalistic. Are you going to suggest that either one or the other is somehow "right" or "wrong?" On the basis of what? A denial of nature itself?
If your answer is no, that you would expect your killing to give me more ethical pause than the killing of a mushroom, then I would hope you can see how the same principle would apply to other animals as well. Plants do not suffer or have conscious awareness in the way that cows and pigs do. Thus I seek to reduce their unnecessary suffering.
And I do not fault you for that, in fact quite the opposite. Does that come as a surprise?
But I am a creature of my time and place, my history and my culture. That, too, is part of our natural world. With any luck, those that follow me, when I'm long dead, will -- because they've grown in another time and place, history and culture, than I did -- have different views. All well and good. (Sadly, they won't be my offspring, but there you go...)
You label yourself a Buddhist, which most of the world takes to be a religious affiliation. All religions, so far as I can tell, seek ways to deny our human nature and try to make us into something else. But we are, in my view, not something else. We are humans. And we possess that nature whether we like it or not. Yes, we can suppress some of it, some of the time, but not all of it, and not all of the time.
If I could have but one wish, it would be that people stopped reading religious scripture, and find their way into philosophers of human nature, like David Hume and Edward O. Wilson. I think they'd be a lot further ahead in understanding themselves, and why they so often seem to falter at even those things they claim to believe most heartily.