They do it just to get out of having a meeting agenda or running a meeting because they are disorganized . They have no responsibility or culpability and just deflect all the responsibility and attention on the presenter.
Thye make it look like the presenter is disorganzed, but they just asked you to sumerize a month of work into 30 minutes without any notice.
I'm 'hiding' in the bathroom to avoid this right meow.