i think most of the kill stealers are newbies ignorant of the culture. and then there is the occasional score monkeys.
it really irks me when i am flying a lesser aircraft for the challenge and somebody comes along and takes my hard earned kill - an aircraft on fire or one floundering with tail feathers shot off - etc - and takes it.
i'm not that good, so when i do a good job out thinking and out manuvering a superior aircraft, i really want that kill. i will leave an aircraft on fire to limp away if he can't land ( unless it is still a threat) to save ammo. it just absolutely ruins my immersion to have to worry about the lame wimps stealing the kill out from under me, forcing me to expend needless ammo because of them.
guilty parties may not care what i think, but i forever brand a kill stealer as an prettythanghole, and i will never speak to them or respond to them in any way again, unless i see mitigating circumstances.