People kill themselfs in situations like that all the time…
Weapon was released by the planet, because the planet itself was in danger (from Meteor and Sephiroth, etc.) Weapon was meant to be there to protect the planet, by locating the source of the danger and eliminating it. (You remember when the Weapon that fought you outside Midgar turned away as the Mako Cannon was to be fired at the Northern Crater, causing the death of a lot of the lifestream, in order to counter that threat, thus trying to protect the planet?)
Also, when you defeat the weapon that’s flying about, it releases Cloud’s Ultima Weapon sword. You could argue that the planet allowed Weapon to die in order for Cloud to gain possession of the sword to give him a better chance of defeating Sephiroth.
Well, that’s my take on things anyways…
the weapons were realised, and Shinra etc automatically took them as a threat…symbolic of human natures hatred of things it dont understand (eg: ufo’s…we’d try and shoot em down and dissect the aliens)
thats wot i thought anyway.
So I don’t think any of the weapons are evil, there just doing there job.