While I do agree that much of what passes for security, I can't say that I've even been inconvenienced most of the time, much less harassed.
It's like any other customer service intensive job... if you have bad apple, it can make a bad situation.
I can say that I've been "harassed" on two occasions by the TSA. Before I start, despite my screen name, I'm a dude (emma is my husky).
The first time was in the early days of the TSA when they'd have random gate searches... I was on active duty and presented my ID and was in first class. I was randomly selected and when I pointed out that I was exempt from the search, the guy got hostile on me and made me take off my shirt (I had a t-shirt on) in front of the other boarding passengers and also took every single item out of my carry on luggage and placed it on the table so everyone boarding the plane could see what I was carrying.
Life has been fine since, but most recently in SEA, I was traveling with my 2 - 2 year olds and an exceptionally belligerent supervisor started to pull the "move her now... move her now... move her now!" thing on me when I put one of my daughters up on the table to put her shoes on after clearing security. This, despite the fact that there were no chairs available for me to sit her down on and the floor was super-grungy. Fortunately, it seems that the TSA has improved the complaint process and someone from the Seattle office contacted me to reassure me that this person and situation was addressed. As much as I appreciated it, it did not help my feelings at the time that we have lost our rights for a dubious improvement in security.