from what you're posting, this is a failure on the part of the EU and not the UK. Whilst ex pats have been living in EU countries, paying into the local economy etc they've been welcome. If this does change it's a prime example of the EU's spite at the result of our referendum to leave and desire to punish us all.
Good Lord, smileless; a perfect example of Leavers hysteria.
The EU is a regulatory entity. Its laws and regulations are intended to ensure smooth running of the Single Market so that the member states can enjoy 'frictionless trade' and be confident that the goods they trade with each other are of a high standard and that purchasers can be confident that what they buy isn't going to harm them in any way.
It isn't a being at all. Attributing emotions to it is just plain stupid.
Negotiations are being carried out according to principles decided by the 27 remaining EU states. They have set their own 'red lines'; one of which being that the 4 freedoms are indivisible. That means that they cannot be split apart. This is not 'spite'; this is member states protecting their interests and the integrity of the Single Market which they benefit from and which we are being forced choosing to leave.
As for EU citizens in the UK and UK citizens in the EU, they have been stripped of their rights by a vote which most of them had no influence over whatsoever. It is very telling that you only have concern for what you describe as UK 'ex-pats' (they are actually immigrants, same as any national who leaves their home country to go and live in another country is); the EU nationals who live and work and marry and have families in the UK don't get a mention.
As I understand it, the EU would have been prepared to give UK citizens in the EU the rights that they have always enjoyed as EU citizens. It was May who refused to reciprocate. Had she done so the issue of mutual recognition of rights would have been settled ages ago. But no, she wanted to use EU citizens living in the UK as bargaining chips. We all discussed this 2 years ago and I suppose the conclusions were much as they are now. Leavers didn't care at all that their vote stripped away people's rights and caused appalling uncertainty and stress for EU nationals and UK nationals alike. But now they're whining that UK nationals in the EU may be badly treated because the EU wants to 'punish' us; that that non-sentient legal entity wants to punish us. How absurd can you get....