What is moral is in the eye of the beholder. If we are nation of law we follow the law and update it when necessary through Legislative branch. As to your example, Obama pardoned few minor drug offenders but it was a drop in a bucket, one time deal. People who voted for decriminalization of of Marijuana had much larger impact. Presidential pardon is a power given to POTUS that is not needed for functioning of a democratic society. It's a power royalty used to have and should be just used for pardoning the turkeys.