I have seen a couple suggestions to be able to disable the Automatic assignee. This is really what I want so that the user is forced to choose an assignee when creating an issue. For some reason this has been deemed as won't fix.

If we cannot have that, can we have a validator that could be used to not accept Automatic? This would still be slightly annoying for the user that forgets to change the assignee but at least it would not result in numerous issues automatically going to the project owner.