I completely agree that this is a useful distinction.
Would "values-based" therefore be an accurate (and less ambiguous/pejorative) substitute for "ideologically-driven" in your original statement?
P.S. Would concern with GHGs, and/or other sustainability concerns fall into your "ideological" category? It doesn't seem to be based on incompatible values (at least not necessarily), but maybe I'm missing something.
If patterns of avoidance looked like what reasonable science-based consequentialist GHG/sustainability concerns would look like, I would be fine with it.
But what I found is that universally people who talk about sustainability make decisions that are worse or orthogonal to the issue, like buying expensive, organic, and low yield crops (fancy fruits and vegetables) etc., instead of cheapest, highest yield, and most mainstream crops and meat from grass-fed animals. And they're very rarely genuinely interested in science behind nutrition, agriculture, energy ...
I have noticed that among philosophers, vegetarianism of one form or another is quite common. In fact, I became a vegetarian (technically a pescetarian) myself partly out of respect for an undergraduate philosophy professor. I am interested in finding out if there is a similar disproportion in the Less Wrong community.
I didn't request that this go into Yvain's survey because I want more information than just what animal products you do or don't eat; I'd also like to see nuances of the reasons behind your diet. There are a lot more shades than carnivore/vegetarian/vegan - if you want to be a vegetarian but are allergic to soy and gluten, that's a compelling reason to diversify protein sources, for instance. I'd also like to hear about if you avoid any plant foods (if you think they're farmed in a way that's environmentally destructive or that hurts people or if you have warm fuzzy feelings for plants, maybe). Here are some questions that come to mind: