I know you're meme-ing, but bear with me.

Media tends to present things as black-and-white because it makes for an easier story to digest. The occasional downside is that people take in the media without adequately critiquing it or pulling it apart and thinking about it. So you get your "something something dark side", or other people operating on advice about anger that they got from children's shows when they were 5.

Anger...yoked to the PROPER cause...is powerful. It can be useful as all hell.

Waking up my anger is how I got myself out of an abusive home--it gave me the ability to act instead of just staying there frozen. So, being motivated by my anger got me out of the situation, which bettered my entire life.

Anger is also how I broke the cycle of abuse, funnily enough. I got so angry that they DIDN'T break the cycle for my sake that I dove head-first into self-improvement to figure out how not to repeat it myself. Anger at them being stupid failures is how I drove myself to be better.

Sure, you can think of anger as something that only ever is destructive--but in the real world, that's not true. It's a kid's tale. You can yoke the motivating factor of white-hot anger to get you out of shitty situations or to improve yourself...and you won't actually get black veins crawling over your skin and red glowing eyes.