Great question. I believe that the answer is twofold - (1) they got greedy and (2) they thought that things would turn out differently. Time and time again they were wrong.

I think they thought Discover would hold and enjoy the rewards of the uplist.

Then the proxy debacle happened. No uplist. Then I think Discover punished them.

And then AMBS had no choice but to go to the devil to take out Discover.

I also think they thought they could pull off a DX transaction which would ameliorate the downside of the deal with the devil.

They seem to have been just plain wrong about everything.

We shall see whether they can pull something off to pull us out of this tailspin.