No, it's the same thing. The purpose of a painting is not to have gleaming edges or colorful patches - it's to awaken emotions. The point of a software application is to allow us get work done as easily as possible. The point of a car is to transport us from one place to another as painlessly as possible.
Success is when a creation achieves the goal of what it is supposed to be. Being great in what you do is the ability to create something that achieves that goal.
Software applications are like paintings. It's easy to create a mediocre painting, and the difficulty in the magnificent paintings lie in the attention to detail.
If you really think usability is not the CORE of any software application, then you are not just on the wrong path, you are going in the opposite direction.
I'm not saying it's not the core. I'm saying that the creator of the interface is in no position to objective judge the usability because they have an innate knowledge of the system because they designed it and they know exactly how it functions and how it's supposed to be used. If you want a real measure of usability, you have to get someone who understands the problem domain, but has never before seen your interface, and then objectively determine how easily they can figure out how to perform tasks and get things done. The fact that you, as the designer, already know exactly how the interface is built and operates precludes you from having an objective opinion of how easy the interface is to understand.
Similarly, a painting's artist cannot objectively determine how beautiful/emotional/successful the work of art is, because he has an innate sense of what it is trying to convey to the viewers. Just because the artist sees the subtles details, nuances, allusions, etc, does not mean that other viewers will be able to glean the same information.
And to drive the nail home a third time, an engineer could not possibly be an objective judge of how easy a car is to operate (usability), because they already know where everything is and how it works. They need to have a real person sit in the seat to realize that putting the cigarette lighter and cup holders inside the center console is a bad idea and not at all intuitive...
It seems like you are defining beauty AS usability. To me they are orthogonal. Beauty is a quality that appeals to my aesthetic sense, and usability is a quality that appeals to my practicality. There are beautiful websites that are unusable, and ugly websites that are very usable, I'm sure you can think of examples for both cases.
I believe perpendicular applies to only two dimensions, while orthogonal applies to three or more. The latter makes sense when there might be more than two dimensions present in the discussion.
Success is when a creation achieves the goal of what it is supposed to be. Being great in what you do is the ability to create something that achieves that goal.
Software applications are like paintings. It's easy to create a mediocre painting, and the difficulty in the magnificent paintings lie in the attention to detail.
If you really think usability is not the CORE of any software application, then you are not just on the wrong path, you are going in the opposite direction.