How incredibly patronizing.
Have you considered that people have different tastes? Personally, I hate eating; if I could take a pill to replace all my nutrition needs, I would in a heartbeat, even if it costs more than my current dietary expenses.
I think "stick with what you know" can be a sound strategy if you are loss-averse and generally content.
Yes. If he'd tried eating a variety of foods and hated it, I'd say fair enough. But how can you possibly know something like that without having tried it? To just dismiss so much of human experience without even considering it is honestly tragic.