Statements like "don't buy meat" are much more of a gimmick than tinkering with cattle feed. The latter is a realistic option -- which might not make a huge difference, but it will make a difference. The former is a pipe dream. Humans have been eating meat since before they were human. Good luck changing that in the timeframe we have before climate change becomes very painful.
Do you think people ate as much meat then as now? The mass farming of animals is an incredibly new phenomenon in comparison to how long humans have been around. And what about driving? By your argument it should be easy to give up considering we only started it recently.
These solutions are simple, but not easy. Therefore people are looking for a complex solution that's also easy and I think we'll be looking for it as the water rises above our necks.
Sorry, it's not a gimmick. There are plenty of cultures which eat far less meat and are very healthy. In my opinion the difference is they know how to cook other food well. Of course I don't expect everybody to stop eating meat entirely, but why isn't it part of the answer to climate change?
