It costs a lot of money to buy. It costs a lot of time to prepare, unless you pay someone else even more money to do it for you. It takes up a ton of space, and even requires you to have a bunch of appliances just for its existence.
All so you can what- get a taste in your mouth and not die? I know that's a gross oversimplification(forgive me for it if you will), but it's always been a hassle I just really don't enjoy dealing with as often as I have to. I want to enjoy food, not be forced into it.
If this is actually healthy- and I want something more than a few people living off of it for a couple weeks- I'd love it. I wouldn't give up food entirely of course, but I'd save it for when I actually want a specific taste, or to go to a specific experience with friends and family.