Actually, I think they do a decent job of explaining that these particular people haven't done a very good job of keeping the animals properly. For example, Burmese Python Guy was drunk, had Cocaine and tranquilizers in his system, and had hit his head (leaving a smear of blood in the doorway of the enclosure) before he entered the snake's enclosure. After he was killed, the snake was taken to...somewhere, don't recall. A zoologist was interviewed who said the snake was pretty seriously underfed and was an "accident" waiting to happen.
I haven't watched every single episode (yet), but so far they have made it a point to say that these people aren't doing this correctly and that's why they've had the problems they've had.