I have plenty of time to make food, but it's not just making the food.
It's coming up with an idea of what meals I want to have each week, it's going to the grocery store and purchasing the food. When it comes to putting it away, you have to decide if you're going to eat this steak right away or if your're going to freeze it for another day. If you have frozen meat, there's a good chance you'll have to take it out and thaw it the night before so you can cook it.
By no means is this an onerous task. It's really all just part of daily life for a lot of people. But here's the rub. If you don't have time (or "lack of foresight") to get your groceries on Monday, you're not going to be able to spend 40 minutes to grill that salmon on Tuesday. You certainly won't be eating the leftovers of that on Wednesday.
I clean the house because a dirty house is distracting and becomes unsanitary. I can even enjoy the process and the satisfaction of making clutter go away. But I don't plan out cleaning the house. I try to keep it tidy as I go, and if it gets out of hand and becomes a problem, I dig in and start cleaning. I don't hire a cleaning service because it's manageable with my lifestyle.
I have a fairly large yard that I have to mow each week. It usually takes me about 3-4 hours each weekend between the riding mower and the pushmower. Sometimes I need to get the weed eater out and trim around the house. For years, I had no problem doing this on a Saturday morning. When I got married, my wife and I divided this job up and it cut down on the time. But when we had my kid last year, we could never seem to find the time to mow the yard each week and by the second week the yard was looking like a hay field. So we started paying the neighbor kid to do it. It became amazing to come home from work and see the yard cut. Just removing that from my list of things that need done became a relief and allowed me to focus on other things that were more important to me (like replying to posts on hacker news ;).
The crux of the matter is about priorities. I may spend a couple hours building a new PC, or more likely, spend time out in my hamshack setting up an PC to radio interface because that's what I enjoy. I make time for those activities. I also enjoy eating or drinking with friends as a social activity. I could have friend over and fire up the grill or we can go to a restaurant and eat. But other things are done out necessity. But when it comes to getting a meal for myself, I could care less. I'd much rather spend my time working on my radios or solving computer problems or teaching my son how to read. Going to the grocery store is really far down on my list of things I'd like to do. But since I didn't go to the grocery store, I don't have supplies to make a meal with.
To get around this, I can swing by any sort of fast food place (Subway right away), I can order pizza, or I can stock up on frozen meals from Sam's Club. My freezer has a lot of 2 minute breakfast sandwiches. But none of these are really that healthy.
So when I heard about Soylent, it struck a chord. I can theoretically by this in bulk, it has a long shelf life, and make it in the blender in a couple minutes. People have done meal replacements before of course, but this seemed to be much more complete than those canned milkshakes or protein bars ever were (and I've tried some of those before). So now whenever I look up from whatever I'm working on and realize I'm hungry, I can make something that (hopefully) tastes good in 5 minutes and take it back to whatever interesting thing I was doing.
Another benefit of this time saving is that you don't have to go right back to work. If you have 30-60 minute lunch window, most people spend the bulk of that time obtaining and consuming food. Imagine having your thermos at the ready and you take it with you to go read a book, or just stare out the window, or maybe you go for a job and eat it when you get back. Most people are focused on the lunch in lunch break, but might enjoy using that break time in a different way.
Sometimes I eat fast food or some microwaveable thing because I am either exhausted when I come home, don't have food in the fridge, and I don't want to prepare anything or go to the super market. If I had a healthy and cheap alternative to a borrito, burger, or teriyaki chicken that would be awesome.
I'm not going to go 100% on Soylent and I don't think many of the people buying into it are, it's a meal alternative and another option for those 20-40% of meals that I simply am not going to cook for whatever reason.
Soylent isn't from another planet and isn't made of some crazy chemicals just invented. Looking at its ingredients list isn't any stranger than looking at the ingredients list of almost any product in the supermarket.
I'm lazy when it comes to food: my primary motivator with respect to food is not being hungry. While I like to eat food and definitely have types I prefer over others, I don't like to source them, prepare them or clean up afterwards. I also don't like that I have a whole room dedicated to the storage, processing and cleanup of food and food-related paraphernalia.
Basically, aside from the 'provides vital sustenance' aspect of it, I don't believe food enhances my life in any way. A product that claims good, fast, palatable nutrition with a minimum of effort? I will give that a try.
If never or not often, why will Soylent be different?
I haven't purchased other meal replacement drinks because I frankly wasn't aware that they existed until I started following all of this.
I also contest your statement that eating healthy is easy, unless by easy you mean 'requires careful planning and constant vigilance'