Soylent is relative to the idea that we men and women don't have to do meal planning, cooking, and kitchen cleanup. If you don't want to cook, or don't want to cook for somebody else, Soylent and other meal replacements are a good solution.
Before "women's lib" in the early 1970's, there were strong gender roles in that women were expected to be homemakers and men were expected to be working a full time job. Women took care of things around the house such as child rearing, buying clothes, buying groceries, cooking, cleaning, washing clothes, ironing and many other household chores. Men put their energy into work and never had to worry about food or clothing. Many men didn't know how to cook!
It seems in those days that men and women needed each other, getting married and starting a family was the thing to do. Many women wanted their men to be paid more because the household would have more income and she can stay home and take care of the family.
Now women want to be on their own - I see this as women getting rid of the man. Women don't have to depend on men. Men don't have to depend on women. There is plenty of evidence in the decline in marriage rates, family households and birth rates since the 1960's.