To address that point and similar ones I do agree with what you say, the answer to the problems isn't simply not killing animals and eating them, it's our very way of life.Most vegans do not understand the impact they have on the environment, from oil based clothing to the precious metals in their phones, tablets etc. If you tell them leather and wool are both sustainable and more environmentally friendly they get well pissed off.
Also point out that if people don't drink milk and eat meat then the fluffy sheep and the cute cows will disappear from the countryside as no farmer is going to keep them as pets. Although very noble, veganism is fuelling massive deforestation in Borneo for palm oil and the Amazon as more is de-forested for soya production.
Yet I think the problem is the people who see a profit in the market more than the actual consumers themselves. The people deforesting aren't vegans, though they are doing it to cater for a demand which they helped to create.
Advertising palm oil as an alternative is an incitement to buy just as much as burger chains advertising on TV.
When I came to Catalonia over three decades ago there wasn't the choice or range of foods that are available today. If I wanted cous-cous or basmati rice, to take a simple example, I had to hop over the border to Perpignan or example. So I just adapted to what there was available locally, and luckily the Mediteranean has a lot to offer.
The main problem is the global market, the ease of finding foodstuffs that aren't local and the megabucks that can be made. Money-men see a possibility and promote it. Capitalism rather than people's choice of diet whether omnivore or not.