Simply put, allow personal claim owners to more easily destroy walls and potentially other objects on their claims by lowering their damage soak towards the claim owner. This benefit should not confer to anyone besides the personal claim owner, regardless of the permissions granted to them, to avoid complicating current relationships and systems.
As it stands, players who construct walls face equal trouble dealing with their defensive structures as their enemies do. While this is a great idea in theory and very realistic, the truth is that it's possible to botch your construction (especially with gates and cliffs), be locked in with your own walls, or simply need to restructure your walls over time as you need to expand or recede. You then either need to invest in a ram and/or a pali basher to break through your walls and modify anything.
Historically, in W3, 4, and 5, players who did not know to seal their cornerposts were often trapped in their own palisades and needed to request either community or dev intervention. This is not a meaningful mechanic nor is it a fun way to fight/be fought. It locks players out of retaining their ancestors on death as any hope of reincarnating with their character entails inheriting being locked within the walls as well. Overall it's stupid.
On top of that, it's painfully tedious if you ever want to modify the shape in any way. For players who do not know the system inside out and who do not know how to meticulously plan their hermitage or village, you will need to modify your walls. Making additions for extra farm land or decreasing land claimed as friends quit/move away means investing large amounts of time to tear down and reconstruct anything, especially if you have a brickwall. Painful tedium is never a good mechanic.
The only people potentially hurt by this are those with palisades but who have opted to not make a claim (is anyone this stupid?) and non-villages who have been absorbed by villages large enough to declaim their claim (but they were already done for so this hardly qualifies as a detracting reason.)