I've read it now and you didn't actually refute anything, so it seems my prediction was spot on.

No idea what you're trying to say here, is a character somehow compelling in a vaccum, without being a part of a story? A writer makes a character compelling. Comic book characters are especially at the mercy of their current writers interpretation of the character, whilst the core often stays the same, the minutia of the characters personality differs.

Yes a character can be compelling in a vacuum because they have plenty of potential for interesting story telling. They have flaws and weaknesses that can lead to engaging conflicts, strengths that can help them overcome those conflicts, and the balance of these two aspects keeps the conflict from being trivial or contrived. A writer doesn't make a character they didn't create compelling, a writer makes a compelling story around that character. Or fails to.

Also it's funny you mention the core of the character because that's exactly what I'm referring to with Superman. The core of his character is flawed. And everything in this list you mention:

Superman is not really invulnerable. He has many weaknesses, many characters have hurt him, even killed him.

Superman is not a god. Some writers inset messianic and Jesus allegories into media, but it's not something that is a frequent plot point as the character exists in a universe of similarly god-like beings.

Superman is not always portrayed as unwaveringly moral and good. In fact you could argue that his stubbornness in wanting to abide by his code of justice is a negative attribute, and sometimes puts him at odds with other characters. This is not always portrayed as "Superman is right". Hell, in his early days he openly killed people which was later retconned.

Isn't simply changing the minutia of the character but messing with the characters core, which is a Mary Sue. Aside from the god part, I mainly just included that for the sake of hyperbole, the core of his character is a collection of powers that make him nigh unstoppable except to his very specific and contrived weaknesses coupled with a selfless do gooder attitude. How exactly do you intend to argue that this isn't an accurate description of the core of Superman's character?

Whilst being a moral paragon may not appeal to you

I have no problem with moral paragons, character traits aren't automatically a bad thing. It's the combination of character traits that Superman has that makes him uninteresting. Which is why all the best Superman stories jump at the chance to change some aspect of him.

Because I have a fairly in depth knowledge of the character? You're kind of a douche, aren't you.

Yeah sorry but just because I'm not swooning over your favourite superhero doesn't make me a douche. Calling me a douche because I'm not swooning over your favourite super hero does make you a douche however. I see as much as you love Superman you don't really seek to emulate him.