In the grand scheme, this is not going to effect their business. It is a small dedicated few who browse these forums. Tanks fail. It's the nature of the beast. They did what they said they would and offered a new one. OP is being unreasonable in expecting what basically amounts to emotional compensation because of his attachment to his fish/corals and what he had created.
I would think more than a few people, who are going to buy a large custom aquarium, would do a search for the companies they are considering for the build.
There is more than a few posts on this forum alone, about builds and people asking for input.
I would hope the OP would post a thread titled "CADlights tank disaster" and link back here, if there continues to be no remedy from the manufacturer.
Personally, I research whatever equipment I'm looking into. Even before this thread, I did not have a positive regard for CADlights, because of other complaints about their products I have read on forums over the years.
I have never owned one of their products based on other reviews, combined with this, I never will.
Considering their warranty as applicable in this situation does not make sense to me.
Kind of like how your car manufacturer warranty may not cover something or has expired, but if there is a defect in the car they are still liable. Like faulty ignition switches, faulty air bags, faulty emission systems...
Faulty engineering or faulty seams in a tank seems like a manufacturer responsibility.