Lower your expectations and steel yourself for bad attitudes at MIA. Don't even try to tell me I'm imagining this because it just happened again 2 weeks ago, this time with the lounge personnel. This happens even though my requirements and expectations are minimal, and my tolerance is high -- I see needless attitude and inattentiveness. While it's not fair to generalize, the pattern too obvious to ignore. I have a charmed existence on AA, with the sole exception of repeatedly encountering grumpy people at MIA. If you know it's coming, you'll just smile knowingly when it happens, and it won't ruin your day.
Going between terminal E and every other terminal requires going through security, so think twice about using the lounge there if your next flight isn't in also in terminal E.