Warrior General Games

I don't understand the process for checking down to different receivers. Look at these two plays.

In this play, the first read is comfortably open from the start of his route, yet is quickly dismissed.
http://goallineblitz.com/game/replay.pl?game_id=1041268&pbp_id=9381007

And in this play, the first read is double covered for the full duration of his route and yet the QB forces the ball to him when the HB was wide open and would have been an easy TD.
http://goallineblitz.com/game/replay.pl?game_id=1041268&pbp_id=9386833

I am having the same thoughts as well. Why can't the QB recognize open receivers. I don't care what the progression is. If someone is double covered and another WR is single covered the QB should throw to the less covered man. Seems pretty simple to me.