A slight bend does not mean a complete breakdown of your left arm. The third and most important portion of this concept is swing vs hit. Ask any Tour player, or local professional, what is going through their mind during the downswing and they will say, to finish the swing. Tour players swing through the ball - the ball just happens to get in the way. The main concern of Tour players is to finish in balance and to be looking at their target.
Amateurs are a different story.
How many times have you seen your playing partners almost fall down trying to hit it a ton. We should certainly be able to win that battle. If the only purpose of the downswing was to hit the ball, it would be called a downhit and we d stop our swing after impact. We all know this is not the case. So the next time you re at the driving range, tee up some balls and swing with your seven-iron.