Joel and Jeff mention that code quality doesn't matter much from a _business_ perspective. In Jeff's case - does the code quality of StackOverflow's internals matter? Probably not. There's no critical information there - so security is not an issue. It makes sense to me that time spent on features is going to be appreciated more by the users than time spent on code quality.
As for the unit tests - I don't think they mean to say that unit testing is a waste of time in general. From what I understand they're saying that unit testing isn't "real actual work". You write unit tests to save yourself debugging and regression testing effort later. If you consider unit tests intrinsically valuable you may end up writing tests for every getter and setter, and that's just a waste of time. They also mention that unit-tests themselves have to be maintained and updated, and if architectural changes break a significant percentage of unit tests then you have to put a lot of effort in fixing your tests.
The .NET framework was even mentioned as an example where high code quality is incredibly important and where all interfaces should be extensively unit- and regression-tested by Microsoft.
> I’m starting to wonder if anyone should be using any of their products.
So happy users of Fogbugz and StackOverflow should leave because Joel and Jeff are too pragmatic?