By that definition, avoiding eating human flesh is also just being picky.
I think there are two parts to the argument:
1. What is considered edible as percieved by our senses and scientifically measurable (i.e. that we have taste receptors for i.e. proteins/amino acids and sucroses (umami and sweet)).
2. What we percieve as tasting 'good; which is more a socially conditioned thing (i.e. hindi not eating beef, jews not eating pork, vegeterians not eating meat, etc).
The argument is, of course, much more extensive, but I trust you to have the intellect to fill in the blanks and I don't need to type up a complete argument. That we don't eat something we may scientifically not dislike is by definition caused by other than scientific factors which rely on argumentation which can be either weak (easily challenged) or strong. Not eating humans has strong arguments behind it (as you just pointed out), but I do not percieve most strict vegeterian arguments to be very strong.
Side note: It should be noted that I believe humanity would do well in substantially reducing their meat consumption, and a strong argument (among a number) would be environmental concerns.
As I previously mentioned... :)
The argumentation that swayed me to become vegetarian for 10 years were my health, environmental health, domestic animal welfare. When I became lactose intolerant, my personal condition overcame my politics. So now I only eat meat infrequently. Truth be told, after those 10 years my health had not generally improved, but would it have declined more had I not been vegetarian? Impossible to say without testing. Which is the challenge with all studies claiming vegetarians are healthier, those are epidemiological studies with which much can be faulted.
From those three arguments, fake meat would only alleviate domestic animal suffering, but to think it would have any other positive effect, I'd be much surprised.