I am a lead designer, and I know that not every piece needs to be a masterwork, but ever piece of software does need to ship.
Absolutely not the case. We're talking about quality specifically, and why someone might choose to pay attention to finer details versus ignoring them.
Your reasons for ignoring details might be perfectly valid and entirely appropriate. The project may not call for artistry and mastery. All very good points for a different discussion.
Don't think for a moment that those who believe high quality is an important factor are implying that it is absolutely necessary. That is simply a false dilemma.
My point was that the ONLY thing that was listed was details being the separating point, and that there is more to it then that. It wasn't meant as a quip just a clarification, if anything a question even, not requiring a snarky answer but maybe a genuine one. But, I forget, I'm on the internet and snarky is everyone's default for whatever reason.
To add what little I can to this, the reason that drives me to go to these lengths is the craft. Design, like code, is a craft. A good craftsman just does not leave mistakes in their work purposely. Whenever I do this it slowly drives me crazy until I either go back and fix it, or drop the project entirely (if there are a lot of mistakes and/or things I don't really like), usually citing some reason like 'it's too messy' or 'i lost interest'.
For me, design and programming are not all about a/b testing, 100% time efficiency, etc. A lot of it is about art -- making something you know is great and shipping it. When you know something is wrong with your work as an artist, it will bother you until it's fixed.