Comment 23 for bug 1539011

I suppose it's because the people who work on those projects (and few other stakeholders) are the ones who decide the importance (hence *priority*) of bugs in them.

Example: critical bugs are worked on ASAP. But if you made this bug critical yourself, for instance, it doesn't mean the team sees it as critical and will therefore start working on it right away. If this bug was then left as critical even though the team didn't sees it as such, the Importance field would lose its meaning and usefulness.