Even if, medically and biologically, this diet is compatible with humans, do people really want to give up eating food for taste? The "spice of life" in a literal sense.

This question is asked every time Soylent comes up, and the response is always the same: no one is suggesting that you never eat regular food again. Just that with Soylent (or other food replacements) you have a healthy and cheap option for those times when you eat fast food because you don't have the time or energy to cook something healthy.