Is this a serious question?
Those wonderful, dedicated, poorly paid, hardworking staff, some of whom are putting themselves in danger every working day, aren't allowed a bit of fun?
How bl**dy dare they practise a dance routine and video it. Of course, they may be doing it before or after they go on their shift, but let's just assume that they're time wasting...
As for 'disrespectful', I think that most people in hospital love the cheerfulness of the staff, it's a boost to their morale. And things like this keep up staff morale, too. I think it's good.
I'm not assuming that the OP thinks negatively about these videos, just getting my bit in