Because not everyone shares your preference and/or discipline for plants. Lab grown meat doesn't require a planetary scale realignment of moral values and habits.
Some might argue that ignorance or apathy doesn't reduce someone's participation as a consumer in a very inhumane and climate-wrecking meat industry down to simply "preference". I do agree it's unrealistic to expect 8 billion people to change their habits overnight, but we are going to see a massive prisoner's dilemma as resources dwindle until that 8 billion number starts falling.
That's a moral judgement about what words to use that has no bearing on causality. Incentives are never a valid justification but they are almost always an explanation. We should care about explanations when trying to solve problems.
I agree, designing institutions around incentives is key. But the discussion around factory farms can shaped around ethics and not morals, and I had taken the opportunity to point out that "preference" reads as unwarranted euphemism in the face of the brutality of modern factory farming, and downplays the agency of the individual as a participant. Past that, we are in full agreement that it's more fruitful to solve the problem rather than sit around making judgements.
