"And if goalies are being irrational, why aren't kickers exploiting it?"
Two reasons I can think of. First, if you shoot to the left or right (particularly top or bottom corner of goal) then the goalkeeper has further to travel to reach the ball, therefore if it is done with sufficient accuracy and power it is harder, or even impossible, to save even if the goalkeeper guesses correctly. In contrast, a central shot, even if hit with high power is often easy to save if the goalkeeper keeps central. Therefore, shooting left or right more often than centrally can be a rational choice if the goalkeeper distributes evenly between going left, right and center - especially for high level players. Secondly, shooting centrally can look a bit silly if the goalkeeper guesses correctly, since it is usually an easy save, therefore it is seen as a bit of an arrogant, or show off, move. Therefore players may be reluctant to shoot centrally - this is somewhat related to the reasoning given for the goalkeepers in that the players want to be seen to be doing something.
Two reasons I can think of. First, if you shoot to the left or right (particularly top or bottom corner of goal) then the goalkeeper has further to travel to reach the ball, therefore if it is done with sufficient accuracy and power it is harder, or even impossible, to save even if the goalkeeper guesses correctly. In contrast, a central shot, even if hit with high power is often easy to save if the goalkeeper keeps central. Therefore, shooting left or right more often than centrally can be a rational choice if the goalkeeper distributes evenly between going left, right and center - especially for high level players. Secondly, shooting centrally can look a bit silly if the goalkeeper guesses correctly, since it is usually an easy save, therefore it is seen as a bit of an arrogant, or show off, move. Therefore players may be reluctant to shoot centrally - this is somewhat related to the reasoning given for the goalkeepers in that the players want to be seen to be doing something.