Honestly, was there anything redeemable about the Ashina state in its 20-year duration to make it worth saving? We only really see it as a military fortress with a leader who appears apathetic outside of personal martial artistry. The local Buddhist temple is rife with child-experiments/murder. Mibu Village is a shithole with residents driven crazy by the water. Even the heavenly Fountainhead Palace is populated by vampires.
At least Lordran is suggested to have once been prosperous.