Well then what is the point? If you're eating one or two balanced real meals a day, eating something ready-made for the calories is very easy and cheap. There's no need for anything like soylent. Have a coke and a pickled egg for lunch everyday.
I would have to consult my doctor, but my guess is that a Coke and pickled egg would meet those requirements.
The founder said in his first blog post about the subject that, prior to pursuing his Soylent idea, he was eating a lot of fast food and frozen burritos.
Of course, if you're just looking for a cheap, quick hunger fix, those things will work. As will a candy bar, bag of chips, etc. But if you're trying to eat healthy, it's kinda tough to find something that's also quick, convenient, and filling. Soylent solves that problem.