Earlier quoted context omitted.
No, it doesn't make any sense. You cannot decide whether a small piece of what you call "UI" is good without considering its place within the larger context that you call "UX". A dialog box that is very pretty, fits well with the overall aesthetics of the application and the platform/OS, and properly does what it says it does—would still be an example of bad UI if it's one of those dialog boxes that shouldn't exist i…
There is an experience to using a UI (bad colors make for a bad experience), but it is not UX. Totally different. Here's how it Don Norman makes the distinction: there is no medium to UX. That's a fairly large conceptual difference. Here's another example: user focus. When an important event occurs, should the user not be able to continue a task and be stopped until a decision is made, or should they continue to work…
Don't be an ass.
You seem to have finally elucidated a meaningful, unambiguous distinction between UI and UX as you see it: UX is purely abstract, can be described with nothing more than flowcharts and probably is concerned with what kind of mental model the user forms for how the application works behind the scenes, while UI is any concrete realization of an interface; any discussion of a real on-screen layout of information and controls would fall under UI rather than UX.
I can see how that distinction could be useful in a more or less academic way. Unfortunately, even using your definitions there are a lot of usability concerns to UI, as I originally claimed but you took exception to. Bad UI layouts can lead to objectively, measurably worse usability (eg. number of clicks required, hard-to-hit targets, etc). Those problems are real: you cannot assess usability in your purely abstract "UX" context and then completely set aside usability concerns in favor of aesthetics when you start drawing a real UI. You have to constantly keep usability in mind throughout the entire design process, even when fine-tuning your final UI layout.
(Your definitions of UX vs UI would also seem to lead to "UX Designer" being a job title in the same vein as the kind of "software architects" who don't contribute at all to writing, reviewing or testing the actual code.)