* If an engineer explained why he preferred Linux to windows, he wouldn't be thorough if he didn't at least have some understanding as to why Linux was a better solution. I would assume some knowledge of the workings of Windows would be necessary to contrast the two systems. One could simply point to a performance metric perhaps, but a great engineer should dig deeper to make an effective argument.
* There are certainly some people who will claim to be experts in a particular area. True experts, in most cases, won't have to say it.
* Trying to make great software to solve business problems should require some understanding of the business problems being solved, no? I don't think you can really solve a problem without knowing what the problem is. Of course, my comments here are assuming that you are building software to solve a problem for a business - the 'business' could be substituted with 'the problem being solved', and perhaps that would make more sense for my statement if you are taking the word business literally.
I consider great engineers to be engineers who get things done and their solution stands up to review over time.
These types of answers are usually tell-tale signs of engineers that are harder to work. But from my 20+ years experience, they are not necessarily a sign of engineers lacking passion.
I've found great engineers who said the following:
* I have no idea how it works (he was talking about Windows and explaining why he preferred Linux)
* I've learned all I've ever want to know about... (he was talking about Visual Basic)
* There is no solution... (reaching a consensus every time)
* I'm an expert in Ruby (he was)
* I don't understand the business... (I'm just trying to make great software)
edit: I removed the Jeff Bezos line. This came from a keynote he made at Stanford. He was really saying that he doesn't pay much attention to his competitors.