I've lived with many different people, and on a general guideline, women in general put more effort and attention to food (I don't live in US, though, so I speak for some other countries).

Soylent surely tickles the nerdy nerve of some people, but (fortunately) real food is still a pleasure for many; adding the fact that it's possible to prepare such food spending relatively little time, I can imagine that people who are already inclined to cook (as above) would not switch to substitute food.