This is absolutely and precisely true. IMHO, the top three motivations of the fervent left are narcissism, resentment, and the motivation to punish those who they think need punishing. It's a very negative approach.
The narcissism is evident in their leadership, and one need look no further than Obama, Hillary, and Kerry to see this. I personally think that activism politics draws narcissists because it affords them an opportunity to ‘save the world’, or ‘transform’ things - like healthcare, or even a country. These people could potentially affect positive changes in the world working in the trenches, without getting personal credit, but they generally won't. This isn't what attracts them. They want to differentiate themselves.
Resentment and motivation for payback are, I guess, different sides to the same coin, but are definitely central motivators for many on the left.
The Slave doesn’t dream of being free, he dreams of being Master.