From your posts I can see you've been working for the wrong sort of people/companies and it can be frustrating when there is not much choice. I've been there. Company Politics is always the thing I find frustrating.
One of my bosses in the past said I could vote with my heart or my head. I voted with my heart.
I think the wrong sort of people are in every company. In the past due to youth and inexperience I've not always handled it the way I would now and ended up being "played" by colleagues. Now I can see it coming a little better and care a little less about being popular. I think any company also can become very political when people are in fear of their jobs.
Here's a fine example of politics in action. One colleague who shall remain nameless asked me to be part of a project team which I knew I was unlikely to be available for the implementation stage. I was aware what was going on, asked to be kept involved but that week particularly I had too much work on (BRC prep). My boss told me
to drop this project and ask for assistance from group. Now I did this and someone from group obviously took exception to this and emailed the project manager with some criticism of me. This project manager was a political a***hole as proven by his next actions. He then cut and paste this email into the meeting minutes which were circulated to some people higher up in the company (I think even the chief exec was on the circulation list.)
Of course I was angry but I figured whatever I did it would not undo what had been done by this guy and I also figured I wasn't the only person who knew what he was like; so in the end I emailed the person who had written the email, apologised for not being available to work on the project and explained why and said how unreasonable I thought it was that her private comments had been relayed. She never replied but I'm sure she expressed her anger to her seniors with the person who had made her comments public. I realised after a bit of soul searching that anyone reading the minutes would have had a negative view of the person who wrote them and the person who had been critical of me and I couldn't do anything about any negative view they had of me anyway. Any explanation would have just looked like I was trying to make excuses (and chances are it would direct people to something they didn't read anyway). 10 years ago, I would have been emailing everyone back, knocking on peoples doors and telling them what I thought. Frankly it doesn't help, you kind of have to find ways to manage your boss and colleagues and beware of the sharks.
Oh and they always get their comeuppance in the end.