It's not a mistake. From the thread where permissions are relaxed:

>How about we make it so that normal users have full privilages except the following:
>
>- Can't bulk change
>- Can't change Importance field
>- Can't re-open bugs in the CLOSED state

For a user user the bug that affects them is always the most important.

We need something for devs to still be able to use.

If you're a triager/developer we can get you edit rights.

David