But as we can all agree, the Dragon Gods are full of crap, since they're way more corrupted than humans ever were, being directly connected to the Time Devourer.
This is all simply Chrono Propaganda.
It's not just the Dragon God, the Dragonians wrote the same thing on Fort Dragonia's walls.
And nothing implies that the Dragon God itself is corrupt. Actually, it was saved if at any least by being split up. They have their own personalities, are each element, and feel the planet. They remember the fact that they were sealed, they may not realise that their actual soul is inside the TD but either way, the Dragon God recombining and merging with Harle probably put them up somewhere really high, and for that reason they were called the Tiem Devourer because they were coming close to becoming another TD, after all, they did want to destroy the humans.
And their views are right. Had Lavos not landed and saved the humans in 65,000,000BC, the reptites would have flurished. But besides that, Lavos is killing the world, and hence what he nurtered must be as bad as him.