I think the largest reason for this change, is because the claim block now prevents spawns. You get someone covering a 300m area with LCB's that prevent spawns, and it really ruins the survival aspect of the game.'
I can agree with allowing more than just one. Maybe 2 or 3. More than that preventing zed spawns isn't really playing the game, and it will break horde and pathing mechanics. If you need that much protection from zombies, you can turn them off.
There is also a fine line here that the developers have to walk. This is a "survival horde crafting game". Which of those do you put first when you're developing? Survival, or the ability to create giant castles? IMHO, the core of the game is about survival, and with the current iteration of the LCB, being able to zombie-proof and area larger than 40-70 blocks is against the core aspects.
Currently it looks like modding this feature will require modifying the DLL, but I'll also admit I didn't really put more than about 5 minutes looking into the data for it right now.