I logged in as all of the users and the WPMU DEV Dashboard plugin menu bar doesn't display for anyone.
I put my define('WPMUDEV_APIKEY', ...); in wp-config.php.
I didn't put any other options in there (like limiting to a specific user).
I might have done too much button clicking when I installed the plugin months ago (haven't seen the menu in months and just haven't messed with it).
Maybe there's a SQL code I can copy/paste to remove ALL WPMU DEV Dashboard options from the database (since my API key is in wp-config.php anyways)???