Vibrating speakers

On another thread just now was a post by Geoff Kait

geoffkait21,280 posts04-18-2020 3:45pm+1

“The only good vibration is one that’s dead.” - Shannon Dickson

Yes, I know what some of you are thinking, “but speakers are like musical instruments. They’re supposed to vibrate!”

Is this so - are speakers supposed to vibrate? I thought it was just the drivers, and the speaker shouldn't.
Or am I missing something?
Hence I use Townsend Podiums for main speakers regardless of floor type