I was relatively lucky in the beginning of my martial arts experience. For the most part everyone's focus was simply on training, getting better and having fun while doing it. We only had a little friction we had with the local karate club, mostly because their teaching style was supremely horrible (their yellow belt test still gives me nightmares)
Post college though, I entered the world of the Chinese martial arts and things changed. While I generally managed to end up with people on the periphery of all the drama, I also saw enough, and spent enough time hearing stories from people who had been training for far longer than me to realize how much ego gets tangled up in the martial arts.
Among the things I've personally seen of heard about:
People creating their own style/organization to give themselves a higher rank
Teachers spreading rumors about each other
Teachers within a style poaching good students from each other
Talented martial artists purposely teaching students the wrong thing for money
Teachers who get offended at the thought of a student learning something from an outside source
Lineage wars (who trained with who and where and for how long)
I could tell you a couple of stories to cover each of those, and I'm still an amateur. I shudder to think of the kind of stories the more experienced martial artists who read this blog could come up with. Its sad really.
Initially I thought this was an issue that was particular to the Chinese arts but as time went on I realized that they seem to be tied into the arts in general, unfortunately. For reasons that probably lie somewhere between ego and greed a lot of people seem to stray in focus from the core idea of training to make themselves better, or teaching to make their students better, and focus on other, more destructive, things instead.
Here's to hoping I never become one of them