Anyone who has ever uttered those words, needs to do the following. Go out onto the ice and have a goalie stand in the middle of the net, at the top of the crease, perfectly in line with a puck about 10 feet away in the slot. Now take a good look at the positioning and the open net the goalie is giving up. There should only be a few inches of room in all four corners.
To properly teach your goalie how to play an angle, we have found "the rope drill" to be highly effective. If you look at the logo above, you will see a version of the rope drill.
With the goalie in correct angle to the puck, but still on the goal line, make note of the open net that is visible. This will convince those goalies that like to play deep in their net that they are giving up a whole lot of scoring space. Now gradually have the goalie move out toward the puck, stopping every couple of feet. Be sure to point out how the open net is diminishing with each move forward. When the goalie reaches the point where only six inches remain open at each lower corner, they have reached the correct location to play an oncoming shot. This location will almost always be right at the top of the round crease. If the goalie comes out any further than this point they are risking the possibility of a deke or making it impossible to recover/react to a pass across. With the goaltender in correct position reinforce the importance of "lining up with the puck" by having each player (forwards too - then they will know what to look for) get down to ice level and look at the goalie from exactly where the puck is, the scoring locations will be few.
Have fun with this drill and involve the whole team. Move the puck location around and continue to use the rope. You will notice that the deeper the puck is into the corner, the deeper the goalie should be. Teach them to envision the ropes at all times.