Most people respect most boundaries most of the time.
Sometimes people don't, and instead react. Now, not every boundary is reasonable, and sometimes it's legitimate to respond and question. However, reaction is not about adult negotiation; it's about overpowering the person who set the boundary.
What are the twelve steps of manipulation?
- Attack
- Threat
- Guilt-tripping
- Gaslighting
- Charm
- Arousal of pity
- Flattery
- Promises
- Contextualisation
- Melodrama
- Waterworks
- Contrition
'[W]e could increase the list ad infinitum.'
How should I respond to such a reaction?
DO NOT GIVE IN, or you'll end up back where you started.
Maybe scan the communications for genuinely new information, but don't get sucked in.
If tempted to relent and withdraw or soften the boundary, check out the situation with a grown-up before doing so.