I don't think the concept of quality is anywhere as complicated as you make it out to be.

Let's take your example of claiming that your software is all very 'gloomf'. So I'll ask you a few questions:

• How do you measure gloomf?
• Who is responsible for checking your software for gloomf?
• How long do you spend evaluating your software for gloomf before it is rolled out?
• To whom do the gloomf-assurance folks report?
• What is the ratio of gloomf-assurance folks to developers?
• Do your gloomf-assurance folks have veto power over software rollout?
• What is the ratio between gloomf failures before your software is rolled out, and gloomf failures after your software is rolled out?

If you can't measure gloomf, I'll know you don't have any, or if you do, it's by chance. If you measure gloomf, but you get it wrong, I'll know you are well-intentioned but clueless. If you don't have many gloomf-assurance folks (with at least some power and a level of independence from the development management) or if you don't give them much time to ensure your software is gloomf, then I'll know you are gloomf-challenged. If there is no discernible difference between gloomf failures detected before software is rolled out and gloomf failures detected (presumably by customers) after the software is distributed, then I'll know that you either have crummy developers, lazy gloomf-assurance folks, or very adventuresome customers (or perhaps all three).

There are a lot of things that can't be proven, but we still can hedge our bets. When you apply for a mortgage, the bank tries to cover its investment by assuring itself that you have future earnings potential. You can't prove that you will continue to earn money, but you can show your W-2 statements over the past several years and demonstrate that, if the past is a decent predictor of the future, you will be able to pay your mortgage. In the same way, we can assure ourselves of quality in future use of software by demonstrating that we have exercised due diligence in the software development cycle.

The happy news for software developers is that there is so little quality out there that even a little can give you a substantial competitive advantage. I used to do QA work for a major online retailer and I took a lot of pride in finding bugs in software before it was rolled out, often very hurriedly. If you have ever worked with a competent QA person, you know that they are worth their weight in gold, and you tremble when you turn your software over to them. Some things cannot be strictly 'proven', but you can provide some pretty decent safeguards and assurances that at least you tried to get it right.

Heck, you might even qualify for a mortgage.