What does "sic" mean?

I just came across an article again, that had "(sic!)" in it, and I finally looked up what it means. I also see it in german text. So it's time to look it up and learn what it means and how to use it when appropriate.

Fortunately there is an explanation in the Merriam-Webster where it is kinda nicely summarized.

What is denoted by sic is that the word or phrase that precedes it occurs in the original passage being quoted or name being used and was not introduced by the writer doing the quoting.

I understand. At least for a second. But how do I know which part is the cited part? So I continue reading to understand it better. But I get a bit confused.

Sometimes the quoted text contains an error of grammar or spelling, but other times it might not contain an error at all, but some kind of language or phrasing that might be unexpected.

Why does it mention errors? Is that really so important when citing?

"Sic" is Finger-pointing?

Reading a bit further in the article, that turns out to be very informative, but also less explicit about when and how to use "sic", a sentence sticks out:

There are a host of etiquette issues that surround sic. Since it often follows misspellings or nontraditional language use, some commentators see it as a means of needlessly making a value judgment on someone else’s language habits.

Ok, that sounds "sic" is kind of a blaming tool or finger pointing technique. Actually, that's also where I found it today in a German political tweet. Am I getting the hang of it? A bit later the article confirms my feeling:

The New Yorker’s Louis Menand describes sic as a “damning interpolation, combining ordinary, garden-variety contempt with pedantic condescension.”

I had to look up what "pedantic condescension" means, but yeah this sounds like a blaming tool. Since I don't feel very much like blaming, at least I try not to, I would stick to this:

You can Also Paraphrase

Sometimes it may be better to paraphrase the text and avoid what seems like haughty comment on another writer’s choices.

There is always some doubt left one may misunderstands and wrong-uses other people's words. Especially nowadays in times of short messages, short attention spans and headline skimming.

The last paragraph ends the article like so:

Additionally, it’s regarded as bad form to use sic repeatedly when the same error or weird spelling occurs in a document.

There is more to that last paragraph but without having read the entire article, it does not make so much sense. Finally, I can just recommend to read the article Showing Off Your [Sic] Moves, and it's not just for pointing out errors (sic).