I agree the striker is not obliged to get out of the way but that doesn't give them the right to drag their leg against an opponent to ensure contact is made. They are essentially manufacturing contact. It's a completely different argument if the keeper comes out, touches the opponent and physically impedes him or knocks him off balance. Contact in itself shouldn't give players the right to throw themselves to the ground.
Sometimes the keeper makes contact with the ball and wins the ball but makes contact with the opponent in the process, to me that isn't a foul. A good example of this was Gomes away against Man United when he clearly got the ball but the ref decided to give United a penalty as he made contact with Tevez. It was a joke decision.
I don't agree re the injury argument, injuries are a part of the game unfortunately. Every player wants to avoid them but cheating to avoid injury isn't right in my opinion.