I think it's just a lack of game sense. For a while, my dumbass brother would just immediately reinforce anyone he saw dead - and would just chuck the beacon as far as he could in whatever direction he was facing.
Hehehe.. yeah. I think we where all like this once.
It's just annoying that your buddy is reinforcing you only to be reinforced a fraction of a second earlier by the nobhead on the other side of the map.
My group used to be like this too, now we call out where we want to be reinforced to, and the person reinforcing casually ignores that request and drops the reinforce pod on the nearest bile titan.
Because you're doing the objective, and the toddlers are doing some crazy s*** in the middle of nowhere. And they die. This is how you get them to focus on the objective. You spawn them near it....
I USUALLY wait for someone near where they were at to reinforce them, if it has been an absurdly long time I will do it and throw them as far as I can in the direction they were. However, if I am with a bunch of noobs that are off doing random shit and dying and we are getting short on reinforcements or time, I will bounce their beacon straight off the objective. A little tactical teleportation usually gets things back on track. Somebody's got to rally the troops.