Because of the stereotype.
We're thought to be fun-loving, bubbly, disorganized, flaky, irrational, emotional, head-in-the-clouds, lighthearted, illogical. Dislikes/unable to confront, cannot take criticism, trouble saying no.
The list goes on.
This is not true for me at all.
I am not a maelstrom of emotions. I am highly logical. I rarely pay attention to my emotions. Emotional people irritate me.
I am not particularily disorganized.
I am not flaky. I am NOT irrational.
I have no problem with confrontation, I don't mind arguing.
I can take criticism. Infact, I don't even care.
I can say no. I can say no and make sure you know I mean it.
I am not a drama queen. I HATE drama. I keep my issues to myself.
But still, I am an ENFP.