I use to think that deaths = twice the assists in figuring out how to value kda. But i've got on board with the kda ratio that riot refers to often, which equates kills and assists. (K + A) divided by D. It is real effective in determining contributions of all members of a kill including the junglers and support.
Also I don't like when people blame others for when they die. Usually its when they are attacked by more than one person. My personal belief is that if I die to my lane its my fault. If I die to a jungler gank its my fault. If I die to a person rotating from another lane then i'll expect an away from lane ping to let me have some sense that it might happen but still its my fault when the death occurs regardless of the notification, and if I get mauled by a 5 man gank in lane that is my fault as well.
You cant blame others for something out of their control, and the best way to deal with something like that is take charge of your own vision. If I had vision of ganks and rotations I could back to my turret, if enough people were coming that turret isn't a safety I could back off of my turret. Vision is key.
The only thing the others need to do is take advantage of the missing enemy laners by gaining the extra laning minion/cs gold and experience to get advantage over the missing counterpart and put pressure on the unguarded turrets due to missing enemy laners.
Kind of pointless to rotate to something that has already happened and can't be stopped, better to trade it for an advantage elsewhere.
So I think the 'There are 5 bottom, where is everybody' comments are kind of shortsighted. Better response should be trade the top turret for bottom please, put hits on mid but careful of rotations from bottom, and jungler the top jungle is open for business if u happen to be nearby it. otherwise help mid/top trade the turret. Those are more helpful comments while ur dead, then "where is my team". :)