[@Jerkchicken]
You have a point, the time jump is very illogical.
I forgot to mention that cities and towns and such are a lot more modern, Take Seles for example: rather than just being village with a few houses, it has grown into what.. I would say Mille Seseau. Maybe a little smaller. Bale, Fletz, and Deningrad are also quite a bit larger.

Its also the life force of the planet that is disappearing, which is causing magic to degrade. It also caused many mines to dry up more quickly than anticipated(illogical!), or collapse. So they wouldn't have as much opportunity to improve.

I know that tying the mines directly to the health of the planet is silly, but I'm a silly person!
Sorry, couldn't resist a stupid joke.

So, how much time would you say it took to do all this and to make people believe that the dragoons and dragoon spirits are nothing more than a myth? If its not possible to have it happened within the next hundred years, what extra upgrades would you suggest?

[@Renny]
There is a kind of corruption going around, the source of it is unknown, but we are going to start in Seles during their Dragon Festival.
Which is basically a celebration to the myth of the Dragon Campaign and the events of the game.