If they're fine with all their plant being ruined due to water ingress and don't care about flood protection, that's up to them, but if they're going to run away and leave unstable energetic materials, that's unacceptable.
At least their pressure relief systems seem to be somewhat working, per their spokespeople (https://twitter.com/keribla/status/903241791264215040), it's far better that the relief valves/discs open up and that the peroxides flare themselves off than they stay unburnt and explode later.
The couple of 100k it would have cost seems a small price to pay for flood insurance. I suspect they don't care and probably have the plant and it's equipment insured for 10 times the value. That's typically how these places operate. Now they can collect their insurance at 10 times the value of the loss.