Here is a situation that happened (the names and places )
GM: As you break in to the Protectorate enclave, a number of towering ironforged surround you. They are sword-wielding ten feet tall golems.
Player: I growl at them menacingly.
[Player rolls well on an Intimidate check vs. 10+HD+Wis]
GM: ...and the creatures recoil in fear, obviously demoralized.
[At this point the GM swears]
As that kind of situation happened to you? I know I've faced it more than once. Although I love the Intimidate skill and use it quite often (based on character), I think there is potential for... not really abuse, but more a case of silly usage.
Back in the days of 3.5, there was a line which disappeared from the Pathfinder rule set that opened the door to such ridiculous situations.
To quote the 3.5 SRD: A character immune to fear can’t be intimidated, nor can nonintelligent creatures. This meant that oozes or skeletons would not cower when your character goes "BOO!"
In Pathfinder, creature types are no longer specifically immune to fear. Reading through the books, everything SEEMS to indicate the fact that intimidate doesn't work on creatures immune to fear, such as paladins. And that the mindless monsters would not be affected by someone growling or threatening them.
But they are not.
You fighter or bard could scare anything he meets by "looking impressive." This just doesn't make any sense.
Looking at the most common fear-based spells (cause fear, fear, etc), all of these have both the "Fear" and "Mind-Affecting" descriptors, thus making them useless against a number of creatures you normally do not expect to feel fear.
How I would fix it
I thought of making the penalties for shaken be explicitly a morale effect but that would really make the shaken condition become much weaker. Plus I think there might be unexpected side-effects to this. So I let that one go.
Quite simple, I would reintroduce the line from the 3.5 SRD, making creatures immune to fear and non-intelligent create immune to Intimidate. This would leave the skill to have a lot of usage while closing off the biggest loopholes. Thus you can dazzle the gelatinous cube with a Dazzling Display of your nunchuks!
What do you think?