Most of the the examples you have listed are observations made by you and your conclusions are too far reaching, in my opinion. There are many reasons for an art group to decide improving general skills is off topic. Do art schools actively discourage skill improvement? What is discouraging exactly? What defines a skill and getting 'better ' in terms of art? What I think you have observed is a small human behaviour which results in a group wide phenomenon. An emergent behaviour from fundamental systems within the human mind.
The science behind the topic is limited, most of what we can do is observation and speculation. I think the best approach is identifying key behaviours through reduction. One key behaviour I observe is how we learn, it is our greatest strength, it is the ability to learn complex topics and actions. The majority of times we learn a new process and its intricate steps, we continue to reproduce those steps exactly without question. Example:
https://www.youtube.com/watch?v=JwwclyVYTkk
The video above demonstrates, regardless of the reason, that we usually copy almost every action when learning from others. For most steps within a majority of our processes we do them without question. Another great example of something we learn but don't often question is the SIN and COS functions within math. This can connect to what you observed, a teacher learned art a specific way and continues to propagate it that way. You come along and question it, but it is already the norm, you are met with resistance. This is the culture of a topic.
I believe that these problems will always exist as they are based on the nature of how are brains function. A solution would be to teach self awareness on this problem so individuals can catch it. I first thought of suggesting, that we should just teach openness to foreign ideas but that can lead to the same problem, where change and openness are an obsession that we don't question or oppose questioning.
Humans like patterns and sticking to them. We like consistency and predictability.
I do not wish to further this discussion since it is off topic and you seem to not understand my point. That said I will give you a small response.
Obviously culture can repress and encourage certain opinions and facts. Just because there is law for free speech doesn't mean you can say anything you want without repercussions.
Sorry, It should be what they censor. A good example is the game Fallout 3, the American company that created it decided to censor a quest relating to the use of nuclear weapons just for the Japanese version. Funny enough, Japanese gamers complained that the quest was removed and they moded it back in. More examples of censored content in western games: the swastika in Battlefield 5 and Hitler's moustache in Wolfenstein. Some things are allowed in 1 country and others aren't , clearly we are more sensitive about that part of history.
I was talking for the average person, of course those groups exist but it doesn't mean everyone is comfortable stating the obvious in public. Western culture is sensitive about world war 2. Look at Japan you can go over there and mention the bombs and their war crimes and most won't care. We see this in comparing how the west vs east censor media such as games and movies. The ideas are public but most people are not willing to state them and risk their social lives.
Good answer, I think the whole topic needs to be explored more. World wide production would increase if we could understand sleeping better.
A simple answer here but the whole concept is rather new to the human species.
You seem to be following my every comment. I hope you hold no bias against me, as that would not lead to a productive discussion. I don't understand the point of your comment, what exactly are you trying to express? Is it perhaps my articulation and word choice? Language and words are a bit more complicated than a definition, sometimes you understand through context. This comment isn't a science, by public I meant out in the open not anonymously on a small online forum.
Let us review ideas and make comments without bias. Expressing that some ideas are so bad they cannot be stated is dangerous because we are ignoring them in favour of a bias.
This is a great answer and should be taught to everyone.