because if you turn them on a game of chicken ensues.
"Oh my gawd!, don't let him in at any cost!!"
I swear when I put my signal on the cars behind me speed up in some form of weird penis envy trying to prevent my lane change. It is totally weird.
Perhaps it is easier to change lanes without a signal.
(Funny immediately after 911 this behavior disappeared for about a week, then the old habits returned. I guess we really did not learn anything from the WTC.)
Only thing is that at 80mph when one of these bozos herds his horse, I mean car, in front of me he just may sever his spine for that lack of warning.
It's really a shame they may never ever again be able to hug or feel their children for their careless lane change.