I would say it has more to do with the experience of the owner than anything else. A tegu is definitely an advanced animal to keep; they can suffer from a variety of afflictions in captivity, but the bigger issue is often their temperament. Tegus can be some of the nastiest creatures out there (definitely not all of them, some are very cuddly and friendly but it takes a lot of work to get there). Argentine tegus tend to be way more docile than their Colombian counterparts, which are actually quite aggressive. At the end of the day it just comes down to your own experience as a reptile keeper. They CAN definitely be really rewarding pets, but are definitely not something to be taken lightly as they do have the potential to be dangerous animals.