From pretty much every angle, this issue has from the beginning been a major mess. The point is of course that the EU is basically a club with its own framework, rules, procedures and aims for now, the immediate future and in the long term. Normally, any/every member will have its own views and aims, some of which will be to some extent outside the club's framework and that member will voice and lobby for those aims and the changes they might require. This has happened and does still happen but the results depend on the amount of support found within the club.
In the UK's case there has been a series of tantrums wanting to negotiate a special deal for the UK, nobody else. There was and is, understandably, unease over all this on both sides, the EU and UK - in the UK's case it revolves about not having got everything on each occasion nor (even) the latest new demands either. The EU's (collective) irritation is evident and something anybody can understand and very many (but not everybody, especially in the UK) can easily understand why.
To me it looks like the EU, although having stated that they would prefer the UK to remain a member (why ?), accepts that the UK government intends to leave. But the EU is not going to run after the UK with escalating promises, rather like a jilted admirer/lover. The EU is ready (they say) to listen to what the UK wants and even consider accommodating their wishes but not unless it suits the EU - why should they ?
The UK says it is leaving - fine, leave, and the EU has pointed to the existing terms of leaving the club. No, the UK wants to get more time and my understanding is that the EU has given the UK more time. The UK has indicated they want to be members regarding anything and everything they want to get out of it but not have anything to do with the duties and responsibilities of membership (following the rules) of the club. The UK wants to reshape the EU rules regarding leaving and much else as it leaves - as always, just for itself. There are a number of words one would use to cover such behaviour in normal life, none of them flattering. Why should the EU entertain such demands ?
Perhaps the main problem is that the UK has a hopelessly distorted idea of its own importance in the universe - its self image is probably some 100 years out of date.