It's classed as off-topic as the question is just reporting a bug. Bug reporting is explicitly off-topic.
how does an average user know it is a bug?
It's something working in a way that you would not expect. You can confirm that there's a bug because other routes still work. Clearly something is happening despite design. A bug.
What does an average user cares if it's a bug?
Well it depends if they want the behaviour they're experiencing to be noticed and/or fixed. If they post a bug report here, we close it and it dies. Their effort counts for nothing and the problem could remain unknown.
If they hop on launchpad and post the bug report properly, the maintainers should see it and triage and decide what happens next.
And to go back to your initial question,
Isn't it a question that people would come to askubuntu for anyways? Would that not be in line with the idea of this site?
If people come here to group around a bug, they're looking at old information. The progress of the bug is not tracked here. It is tracked on Launchpad. That is the only place people should be going for Ubuntu bugs.
So no, it's off-topic for the betterment of the Ubuntu community and Ubuntu's development process, and it should stay that way.