The idea is to allow ruleset settings to decide which weapons in whose hands get self-destructed and which not. This suggestion is aimed at mods (FMP *cough*) that have humans factions as well as aliens using earth-based weapons. The humans don't necessarily link their weapon to their mind, while the standard weapons aren't even capable to self-destruct. So if a mod wants to use it, it can use the self-destruction feature while deciding the behavior of the items in dependency of who is using it.
For example:
Plasma Rifle in Sectoid's hands - PR and Sectoid are both set to true for self-destruction. Weapon is gone.
Plasma Rifle in Man-in-Black's inventory - PR is set to true, but MiB is set to false. Weapon drops.
Rifle in Sectoid's inventory - Rifle is set to false, Sectoid is set to true. Weapon drops.