You can still make an exit and be graceful about it. Clearly in their message they mention that user's trust was important to them. I believe that in that case the best reward is to be honest with them.

If I was an entrepreneur I would be rather annoyed by that kind of message because user's trust is a shared resource. It's selfish. Soon enough start-up will start to be negatively connoted. A sort of Made-in-China in the virtual world.