I think there are enough examples of people who've said or written stuff in anger or frustration and regretted it afterwards that I'm inclined to think twice.
I probably wouldn't recommend the anger state to everyone. Just those of us who have found from personal experience that it has its advantages. My default state is carefree and flippant - which results in all sorts of problems if I forget for one second that communications can be taken by rivals and used for their personal advantage. This has resulted in many a regret.
Anger on the other hand provokes goal directed thinking, improved attention and decisiveness when it comes to determining and protecting my interests, whatever they may be.
Unfortunately contempt seems to result in the worst of both worlds. My instincts seem assume that just because someone is blatantly stupid they can't be a viable social threat so I am both flippant and opposed. Big mistake. Contempt is a more useful emotion for people to feel when their contempt producing instincts are finely calibrated to what level of status they can get away with conveying that the object should have in the eyes of the applicable audience.
**Note: I'm not a poet. I hardly ever write poetry, and when I do, it's usually because I've stayed up all night. However, this seemed like a very appropriate poem for Less Wrong. Not sure if it's appropriate as a top-level post. Someone please tell me if not.**
Imagine
The first man
Who held a stick in rough hands
And drew lines on a cold stone wall
Imagine when the others looked
When they said, I see the antelope
I see it.
Later on their children's children
Would build temples, and sing songs
To their many-faced gods.
Stone idols, empty staring eyes
Offerings laid on a cold stone altar
And left to rot.
Yet later still there would be steamships
And trains, and numbers to measure the stars
Small suns ignited in the desert
One man's first step on an airless plain
Now we look backwards
At the ones who came before us
Who lived, and swiftly died.
The first man's flesh is in all of us now
And for his and his children's sake
We imagine a world with no more death
And we see ourselves reflected
In the silicon eyes
Of our final creation