By extending his middle finger toward the bench players of the opposing team, Johnny Manziel exhibited a lack of restraint and unsportsmanlike behavior toward fellow players. It is a player's responsibility to conduct himself in a respectful manner, and obscene gestures should not be accepted. Lapses in judgement resulting in rude behavior will happen, but are unacceptable in a workplace. There should be a minimum penalty invoked to send this message loud and clear.
Yes, I believe that Johnny Manziel should be penalized for his behavior on the field vs the Washington Redskins, because they are role models and their behavior reflects poorly on others. Those involved with the NFL need to know that if they misbehave they will be penalized, because it reflects on the kids who watch.
He is a child and he needs to learn that this behavior won't be tolerated in the NFL. No one wanted to draft him because he is a hot head and this just proves it. There are families watching the game and they don't need to be exposed to his immature vulgarity.
As a sportsman you are not only representing your club, your team, you are a source of inspiration, I believe, to millions of spectators on field and on the TV. Such behavior is completely unacceptable in my opinion and should be penalized to prevent this attitude and behavior from becoming acceptable and widespread.