Truck cruiser makes the point that cruising isn't for everyone and that's sure true. I have friends who would never cruise. They're worry is feeling claustrophobic being "stuck" on a ship. Of course we cruise fans know that's not true. I recall one early morning sitting in the lido cafe before it had been open for food service other than coffee and pastries. We'd sailed the evening before so this was the first morning. And as I'm looking out the window watching Dall's porpoise race the ship there was a woman a couple of tables over complaining to her friend how bored she was and what a big mistake agreeing to go on a cruise was. Unless she later changed her mind, she was in for a long week!
I would never tell someone that they "must" go on a certain ship, type of cabin, or itinerary. I'd give my opinions of course but also let them know that they need to weigh their wants, likes, dislikes, when deciding on a cruise.