Doesn't seem like this thread is that active, but I'll post my opinion anyway...
To me, the games heavily suggest that Lavos brought chaos and corruption and evil or w/e you want to call it to men. That's not to say that such things didn't exist beforehand, just not in men; before Lavos crashes, Reptites are already civilized and organized, but exhibit 'evil' emotions. If evil and civilization are connected, Lavos 'indirectly' brings evil to men.
Now, I am not at all saying that it is even remotely possible that the people in Ayla's time were completely pure, rather, that the game is a fictional representation. Thinking about this reminds me of a time that I heard this girl talking about how much she disliked Kingdom Hearts (the original) when she found out that there actually was a Door to Darkness and that the whole thing wasn't metaphorical at all. To me, everything in KH is a metaphor... I can't really find a good way to put how hearing this may me feel into words, but I feel like the entire KH is a metaphor that should be applied to the player's life, not like everything leading up to the end of the game is a metaphor that should be applied to Sora... The more that I think about this, the less it seems relevant