Mostly this was due to the travelogue aspect of the show, with Gates describing the inconveniences and minor humiliations of traveling through the less developed parts of the world, such as his shock at discovering an electrical outlet in the shower of a Peruvian hotel room, or the ridiculous rental cars of most non-North American countries. I had the sense that Gates was in on the joke, and that no one involved took the elusive dragons, sea serpents, and other assorted monsters seriously. More often than not, in early seasons Gates concluded each investigation with qualified skepticism and plausible alternatives to the existence of mythical beasts.
But in recent episodes, something has changed. Ghosts are now featured as frequently as monsters, all the better to cross-promote SyFy propoerties. On the one hand, the mystery mongering has stepped up a notch, with the aforementioned Ghost Hunters stepping in to proclaim every electronic blip and bloop evidence of communication from BEYOND THE GRAVE. Skepticism has largely been abandoned in favor of proclaiming the likely existence of the the beasts. On the other hand, the producers must have noticed that the humorous travelogue was the show's biggest selling point. Now Destination Truth plays as bad comedy, with obviously scripted scenes and over-the-top silliness that would embarass Sesame Street.
I'm not entirely sure what my exact complain is: that it now takes the monsters too seriously, or that it is too silly, or both. A particularly egregious example aired this season when the team traveled to Kenya in search of an evil mythic beast locals insisted was not a lion. They described a hyena to a T, and video surveillance caught a hyena on tape in the area. The show spent money on the trip gosh-darn-it, and we will sit here pretending not to recognize a hyena no matter how obvious it becomes until we fill up the hour!
At any rate, I used to like Destination Truth quite a bit, but I can't recommend the new tone of intentional silliness coupled with enforced credulity in the face of facts.