About 13 years ago I took my first cruise, and from that point forward, about yearly or more, I cruise (though it's been two years since my last). I prefer Royal Caribbean (and Carnival is low on my list, though I've cruised with them many times). I always joke that it's the perfect vacation for geek decompression: it's on a ship where getting in contact with me is very difficult and expensive. Internet is expensive and only somewhat works on board. You don't have to think much -- very little upfront planning is required -- and there's a lot of time spent being left alone with your thoughts. It's very uncomfortable, at first, having to wait in lines without being able to pull out your smart phone and be distracted by Facebook/Reddit/Twitter, but after a day of it, you're forced into a form of relaxation that's missing from life these days.
The biggest reason I love cruising is the staff. Reading an article like this, you'd expect the staff to appear unhappy or otherwise be less than stellar. And while this is anecdata, at best, in the 15 or so cruises I've taken, I've not only never encountered a member of staff that had a bad attitude, I've never encountered a member of staff that was willing to ride an elevator with me without smiling and asking how my vacation was going. It's been impossible for me to find a member of staff who appears, at all, to not be having fun, even though we know full well that they're very underpaid and treated poorly by the western standards that almost all of their guests come from. I've stayed in high-class hotels in specialty suites for work and haven't experienced the quality of staff that I've received staying in an interior, windowless state-room in a small ship. This very personal interaction, with unbelievable attention to detail[0], is why I keep cruising.
These men and women not only work hard under poor conditions, they do so with a work ethic that you'd be hard pressed to find in the best paying jobs in the US. Part of this was pointed out in the article -- in a lot of cases, this is the best job they can get to support their family back home. My wife and I are very extroverted and a ship filled with people who, at worst, are pretending to want to get to know you and make your vacation better is a guarantee that we're going to make friends (genuine or not, though I've never gotten the sense that it was anything but genuine). We got to know a few members of maintenance staff (one of them broke several rules[1] to show us parts of the ship that were off limits, including crew quarters, pre-9/11). These folks know the best places to visit on the islands and where to go to get goods and services inexpensively[2]. One point that was made is if you want to reward a member of staff, cash is king and conceal cash tips from view. They do everything they can to make extra money on the side (and I chuckled because our guy was "a Christian who rented DVDs" and DVD players though I doubt it was the same guy from the article). On one of the cruises we took, we were told that the mandatory tips that are included in your bill (it wasn't always this way) are pooled and your room steward/waiter aren't going to be rewarded directly from any extra generosity you offer[3].
[0] My daughter once worried that the towel animals were not comfortable sleeping in the room because they were placed on the covers -- this was said to us within earshot of the room steward. The next time we arrived in our stateroom, the towel animal was snuggled into the bed with its head on the pillow. Seriously.
[1] We were told that many of these rules can be broken without consequences if they're being broken at the wishes of the guest.
[2] We ended up on a tour on St. Thomas, paid for with a ten dollar bill for the two of us, that was filled with Royal Caribbean customers who had dropped $55/ticket for the same tour. We were told, wait until the afternoon and show up when they're loading customers on. Someone will be standing outside selling off the rest of the seats. Our "bus" was half-empty, to boot. In another case, we were pointed in the direction of a restaurant off the beaten path, filled with locals, where we were fed two large meals with appetizers and bottomless drinks for about $7.50 and it was the best food and drink we'd had off-ship that week.
[3] We learned some more disturbing things, as well. Casual sex is rampant. We were told of several stories that made the lower decks sound like they have a frat house/orgy atmosphere (this is something I've heard from folks who work at Disney and other resorts).