Super User is a question-and-answer site. As such, questions on it should be specific questions or problems that need to be solved.
If you were going to post a bug report here, you would absolutely have to frame it as a question. Just saying "this is a bug triggered by X and Y" isn't really a question. Rather, you could ask something like "when I do X or Y, bad thing Z happens - how do I make it not?" With that kind of question, it doesn't matter whether the cause is actually a bug or not; the focus is on making your computer do the thing you want. Answers to these questions should address the problem, presenting a fix or workaround. Answering with simply "it's a bug" isn't helpful, but a thorough explanation of the internal machinations that trigger it might be.
There shouldn't be a tag for bug reports. Rather, questions stemming from suspected bugs should just be tagged as normal (with the OS, for instance).
Stack Exchange sites aren't bug trackers, so I'm not sure that we could "pressure" any company into fixing anything. The count of upvotes on a question does indicate its usefulness, though. Also, I have already found some answers to baffling, commonly-asked-around-Microsoft-forums questions only located on Super User, so we seem to be doing a pretty good job of filling in documentation gaps already.