There you go, it's not simply disagreement, it's that and much much more. Boris is coming to the EU with a disagreement and nothing more, hence it's not a negotiation, it's simply a disagreement.
Actually he is quite clear that negotiation is more than just disagreement and Boris has brought nothing new to the table, hence there is nothing to negotiate. Perhaps you need to watch it again while actually using your ears and your brain.
I can just imagine how it goes when you negotiate your salary:
access: I'm not happy with my salary.
bossman: well what did you have in mind?
access: (crickets chirping)
bossman: look, if we're going to negotiate your salary you need to tell me what you expect, what you want.
access: (crickets chirping)
bossman: look, this is not you negotiating, you're just disagreeing with us over your salary
access: don't be daft, how can you say that, disagreement is part of negotiating.
bossman: ok, well then tell us what you want and we can take it from there
access: (crickets)
Almost everybody in both the UK and the EU have a vested interest in brexit not happening. It's a stupid idea that will negatively effect everyone except a few wealthy brits who have a vested interest in a no deal brexit. Of course the eu will try and give the uk as much time as possible to come up with a deal or cancel brexit, duh. but they will have to close the door eventually and get on with things