Jolly good... but it's more your opinion than actual observation. And simply because the Buddha chose to do something doesn't make it 'correct' for anyone but him, and he said as much. If you, personally, can't meditate on a diet that contains animal protein, then that's fine. Go to it. The issue for me is the 'one size fits all' mentality. If one size DID fit all, then the Hindu Pantheon would be a lot simpler, the teachings of the Buddha would be about 5 sheets of legal paper single spaced, with all other religious documents being of that magnitude.
However, it's your view and you're welcome to it. I've met any number of vegetarians who are complete drama queens, and who fly off the handle if you're wearing leather. To me, each to his own... No one seems to address that Tibetans generally eat vast amounts of meat, yet founded one of the most populus sects of meditative/contemplative religions on the planet, with only a couple of wars to their name post Buddhist era and, by and large, a terminally sunny good nature, although there must be miserable ones.
The question was can one meditate on an omnivorous diet. The short answer is 'yes' and the long one is 'yes, you can'... but the necessity is adiaphora, something you can observe or not without impacting the core teachings, and smacks of the whole hair shirt thing to me. It's like head shaving or prostrations. Great if you actually want/need the theatre, but not broadly necessary to achieving what you're aiming for.
So, objectively, it's down to the needs of the individual, rather than an overarching requirement.