Not sure what Ned's reasoning is, but my problem is that so few people are prepared for such a fish.
They get very large, are very active, and need a ton of space to swim. They also really should be kept alone, though I've heard of a few cases where they've excepted a tank mate or two.
Eventual tank size should be larger than most commonly available tanks - I'd look into perfecto's line of 3 and 4 foot wide aquariums.
Anyways, if people are up for it and have the resources, more power two them... they look like amazing fish. For me though, I've had great experiences keeping Tetraodon miurus, Carinotertaodon salivator, irrubeso, and travancoricus, and there are still a bunch of smaller species out there I haven't had the chance to keep yet.
Cheers
Sam