Blamers are not usually good at negotiation and other forms of compromise.
That's a direct quote from Bill Eddy's book, Splitting.
Giving in and compromising can feel like abandonment or inferiority.
On our side of things, making large concessions does not lead to long-term peace.
I found a mixture of setting an unreachable goal on the table helped because then it gave me some room to whittle things down to halfway, which looked like a concession when it was in fact my (reasonable) goal. That allowed my ex to feel like he was winning.
The person who actually taught me that was my ex, a former trial attorney

He did not practice his own advice, thankfully!