Every person had an anger too.
Not sure how you got the notion that the film makers thought anger is bad.
Inside Out's is a dissatisfying explantion for emotion, because each emotion-character themselves exhibited a variety of emotion (e.g. Joy was sad), implying by the conceit of the movie that they each had a set of emotions within their own head... ad infinitum. That's the problem with the homunculi theory of mind: it doesn't explain anything.
Did anger ever make a useful contribution in the movie? IIRC only a source of humour, or a problem to be worked around.
BTW The outtake-like scenes at the end included a bus driver who was all anger.
None of that means that they are immune to their cultural and corporate biases and zeitgeist, but you seem to be implying something much more intentional and predatory. Why?
Fundamentally, these people are artists.
What's the state of the world that you want? Does being this angry help you get it there?
Do you also hate the Muppets? Or are you just trolling now?
That said, I look at these sorts of films like the old fables and many newer children's stories: they personify various aspects of life (in this case, emotions) in order to simplify them at first glance for easy recognition and then as a vehicle to show where those seemingly simple things can also be complex and unpredictable.
It's not even just kids' stories that do this. Plenty of movies and other stories use archetypes and "avatars" as characters. It's shorthand that makes it easier to jump into the narrative. Often they're combinations of different stock characters but the kids' stuff is often simpler.
Either way, I grew up with plenty of kids' stories where you knew who the good guy was, who the bad guy was, who the rogue/trickster was, etc. It hasn't stopped me from appreciating more subtle or complex characters and stories as an adult. It's almost as if you learn the basic "language" of characterization and storytelling first, and then can appreciate more varied combinations that as possible with experience. At some point, the fact that certain traits and behaviors are unexpected becomes a big part of a more "grown up" story's appeal.