That's an idea but the "iwg-hide-dashboard" plugin requires the "Role Manager" plug to work. I tried Role Manager recently. It gives you the ability to create new roles, something I would very much like to do. Unfortunately, these new roles remain even after you deactive Role Manager. That might be all right BUT if you decide to change one of these new roles back to a standard role after deactivation, you can't do it. In other words, activating and using Role Manager is a one way trip. It doesn't clean up after itself after you decide that you don't want to use it anymore.
I backed up my database before testing Role Manager and, after discovering these issues I deactivated it, dropped the database tables ane imported the backup files. That's the only way to clean up after Role Manager. I'm happy that I took this precaution before activation it. Of course, this procedure won't work if you don't use it immediately. Once you have made any other changes to WordPress, you will lose them when you restore from backup.
Bottom line: I still need what Role Manager can do but I don't like plugins that don't remove themselves completly when you decide not to use them for some reason.