It's not that they don't understand; that's too excusing/gives them too much credit. It's that they deliberately do not care, and see "discourse" solely as a fight to be won by any means necessary, including blatant bad faith.
Lol, when I was watching it I was thinking it was funny how many times she said thank you. I just rewatched and counted 27 thank you’s. And quite a few good evenings. The crowd wouldn’t take the hint so she had to keep saying it till the simmered down.
That has to be the loudest crowd she’s ever had to settle down. She’ll likely eventually learn what the Obama’s learned. Eventually you just need to start talking and people will stop clapping because they’re excited to hear what you have to say.