To me it is a question of love for sentient beings, is it not the choice of a Bodithsadva to renounce to Nibbana to come back to earth,to try to have all sentient beings enlightened?
Yes. But another way to view it is that we are all interdependent, including on the physical level, and that is how this plane of existence is set up. All things take in nutrients on the physical level that they need to survive from other living things, whether it is plant, animal or mineral. Recognizing that interdependence is part of Buddhist practice. So there is a way to intake food, including meat, and be thankful for it, grateful to the animal that has provided it, and aware of our interdependence with that animal. Some day our own body will die, return to the earth, and nurture plants and animals in return.
Of course one's view on vegetarianism is also partly dependent on one's view of whether humans are naturally omnivores or not. No one believes the tiger is evil for eating meat - it is just part of the natural cycle of life.
So interdependence and gratitude are part of practice, among those Buddhists who are not vegetarian. The other aspect is the ethical treatment of the animals being eaten. As you know, the Buddha was not vegetarian, he would eat meat when given it by others, and instructed his monks to do so also.
The practice for them was about not being part of the killing directly, and of course for some Buddhists that carries over into attempting to not kill any living creature, including spiders and other bugs etc. But as we know this is virtually impossible - we are bound to step on an ant at some point. So it is not about getting crazy, and there isn't some point system set up in some magic book somewhere keeping track of how many ants you do or do not step on. As you know, Buddhism is not about some karmic point system, or rewards.
It is about our awareness, and what practices open us to a true realization of interdependence and compassion. And some lineages do this through practices that include vegetarianism and others through practices that focus on gratitude and mindful consumption of any meat eaten. I think either way, it can be a practice that develops compassion, or it can be a practice that develops self-righteousness. In the first case, it furthers one's path, in the second case, it actually harms it.
It is like the story of the 2 monks crossing the river, which I am sure you have read. There is a young woman who needs help crossing, but both monks have taken vows not to associate with any women. So one monk refuses, but the other agrees, and carries the woman across. The other monk gets more and more worked up about this as they walk along afterwards and finally says, "How could you pick up that woman and violate our vows?" and the other one says, "Brother, I put her down a long time ago, why are you still carrying her?"
Which monk's awareness was in a more compassionate, awake place? The one who adhered to the vow in the strictest sense, or the one who did not, but did not cling to it? The point of this story is that any practice or vow can help or hinder us, awaken compassion or awaken self-rightousness, and I include vegetarianism in that. So it is about how we practice, not just what.
Just my humble opinion as you know!