No one is advocating eating that much cauliflower.
You’re right that a lot of smoothies and juices out there are junk, full of too much sugar and/or having ridiculous amounts of something we don’t need very much of.
But it is possible to juice in a truly healthy way. And people may do it for different reasons.
Let’s say we juiced one carrot, a big handful of kale, a big handful of spinach, two ribs of celery, a cucumber, some fresh lime or lemon, and a little mint. Maybe throw in an apple, too. You have to admit, that would be a pretty nutrient-laden beverage, yes?
Let’s say I’m super-duper busy. I might not have time to sit down and eat all my recommended daily servings of fruits and vegetables. But if I could drink those fruits and vegetables on the go in the morning, I would feel better about having to settle for a convenient granola bar for a meal, later in the day.
Let’s say I have a medical condition that affects my GI tract. (Or maybe just makes me feel crummy.) I might not be able to easily digest (or eat) all my recommended daily fruits and vegetables in whole form. But if I could drink those fruits and vegetables, I’d still be providing my body with the nutrition it needs.
Let’s say I have sensory issues, and I don’t like crunchy stuff, or slimy stuff, or the smells or appearance of a lot of food. This might be so unpleasant that it’s difficult to make myself eat the recommended daily servings of fruit and vegetables. But if I could drink those fruits and vegetables (and maybe doctor it up so that the flavor, smell, texture and color are acceptable) I’ll be getting the benefits of eating them without it being a miserable experience.
Different strokes.