Currently supported entities have separate game rules which define their ability to destroy blocks.
The game rule must be set to either true or false.

Users may only care about controlling a subset of entities behaviour but not be concerned about the others. However, if the value for the default rule is changed it would require changing the values for all of the rules the user was previously not concerned about.

For example if the user wants to only disable Enderman block pickup/placement but keep everything else enabled they would set the Enderman rule to "false" and all other rules to "true".
If the user then wanted to disable all mob griefing they would need to set each individual rule to "false" along with the original "mobGriefing" game rule.

It should be possible to specify that an entity inherits the global mobGriefing game rules' value.
This will give the user more flexibility and remove the need to update multiple game rules if the user desires to update the default rule.
Users would be able to specify entity behaviour which should never change regardless of the global rule value (entity specific true or false) or entity behaviour which should follow the global value (inherited).