I'm late to the party on this one, but I thought I'd throw my two credits in. Our group usually forgets that the fear rules exist, but when we do remember them we try to use them. One thing I like about EotE is that fear is "only" a black die. As noted elsewhere in this thread, that's not too harsh. It's not like other games where it forces the character to run away without taking other actions. If anything, a character being able to triumph over fear can only enhance the story.
I'm generally not a fan of mechanically enforcing role-playing but I think in this instance there are clear benefits and I would like to get my players at least showing some semblance of normal human behaviour in the face of death.
Do you give setback dice to someone trying to do something while running through rubble? If so, why are you mechanically enforcing role-playing? The player could describe that they trip on a loose piece of rubble. There's no need for setback dice to be rolled.
I see the fear rules as a mental "rough terrain". The setback die is the human behavior of not wanting to die. It represents an adrenalin surge, shaking hands, uncertainty, ect. The subtle things that an outside viewer may not notice, the things that are exaggerated in film to show the audience that the character is scared. I would agree with not enforcing rules that take actions away from characters, such as enforcing running away without actions. In this game the character just has a usual setback, just like running through rough terrain or anything else that adds a simple black die to a check. Not that big of a deal.
Give the rules a try and if your group decides they don't like them then get rid of them. Maybe chat with the players about the fear rules and the times you might use them. Will you reserve them for when the group is going up against crazy odds, like an AT-AT or the man in black gunning for them? Or will you use it more often than that?
Happy gaming.