Our priority at Armory is security
Security is not a product of just having no known exploits. Sledgehammer has no exploits, but it's ridiculously cumbersome to store bitcoins in it. If your product is as good at being a wallet as sledgehammer, you have a problem. Usability has as much to do with security as access control. When using your product ends in denial of service, it's security failure.
My quote also implies that we can't just implement a random fix and call it a day. It needs to integrate with the model properly and be thoroughly tested. There has been quite an effort deployed to overhaul the backend, which should hit the next release. It will offer a lot more stability, speed and scalability. Scalability we can leverage to implement other sources for the blockchain data and hybrid modes, in a way we think is robust.
The DB version of Armory was introduced in 0.90, and it should be overhauled for 0.93. You are using a proof of concept version and will get to enjoy the rock solid implementation in 0.93. This is the speed at which we deploy releases, and keep in mind 0.90 was essentially a single man effort. Generally the full blockchain approach was the cheapest solution to implement, and these kind of choices are easy to make when you are putting a proof of concept together. 0.91 was mainly a 3 job, and the whole team of 5 worked on 0.92. Now that we are functioning at full capacity, a lot is getting improved, and much faster.
Also, before we go after this particular issue you suffered from, we had to address the scalability issue that affected a lot more of our users. In contrast, your issue is actually fixable at the cost of a fresh blockchain download, which we did speed up with an integrated bootstrap downloader in 0.91. Keep in mind we identified this issue while deploying 0.90 test releases. This is isn't ideal of course, just side stepping the issue, but cheap enough that we offered this solution while working on something a lot stronger.