No, their metaphor was not ignorant at all.

I was half-joking, but yes it was ignorant? Lesbians don't choose their sexuality, but people do choose to be vegan. There is an ignorance of sexuality and diet there. Also, people do try going vegan, eat some fake meat and cheese, and eventually go back to eating meat because they still crave meat in itself. This does happen. This is also related to those people who sneak in or revert to eating meat because of some cultural or family tradition, or peer pressure from friends. One vegan I knew who was going on for 25 years ate a steak to impress his business friends instead of speaking up to say he didn't want to eat at a meat-only restaurant. Take a look at my other comments here, I am speaking about this topic at the social level, not how individuals like the taste of meat or fake meat.

there is nothing wrong with it at all

Yeah I know, I have been saying that. This is not a moral argument. This is a rational one, and one perhaps from a medical or public health perspective: the cultural desire to obtain "meat" as a thing in itself is the cause for the demand of meat or meat alternatives. It's great that under capitalism that solutions can be provided via the market and supply-and-demand, whatever, but it doesn't address the reason why there is a demand in the first place.

How I know it's a cultivated desire: it doesn't exist across cultures. Hell it doesn't exist within the western fake meat market itself: how much fake seafood do you see engineered out there? Or exotic meats ie objects perfectly engineered to mimic dog, cat, or even human meat? I'm sure human taste buds can enjoy long pork, real or fake. Yet basically no one is asking for this right?