You can change it if you like....go to the file course/category.php and change the occurances of isadmin() to iscreator(). But be careful of what you wish for.
You also need to make the same, single change in the course/delete.php file for it to work.
The former. Do you trust the professionalism of your staff?
Well I've just tried this, and it looks like it allows a creator (after the changes) to delete ANY course, which is not what we want!
I've had a look at the database tables and I dont see that the creator info is saved with a course. Thus it is not really possible to tie in the specific creator with priviliges to delete the course. Of course if a creator id field was added to the mdl_course table then it should be possible to interrogate this, and allow the user deletion rights if they are the creator.
We're in the UK and like you were concerned about this. In the event, our concerns were groundless - no courses have been erroneously deleted at all.
IMHO, although adding a creator field and checking at delete time would represent a technical improvement, I think it'll be far more convenient to await stuff like user defineable roles, which will hopefully offer the granularity to tie issues like this down.