Police the behavior of users
Not everyone is a unique and special snowflake. Some people are just jerks. Wikipedia is not psychotherapy: We can't expect the project to cure bad behaviour. I think some aspects of Wikipedia do tend to bring out the worst in people, so you're right that changing the environment can help, but there still needs to be a mechanism to deal with people who are unable to control their own behaviour.
The success of that mechanism, at least on English Wikipedia, is largely determined by how many friends the person has on the projects. Many friends and you are untouchable, few friends and you are cannon fodder. It's only workable because the worst jerks usually have few friends. If fails when the reverse is true. The whole process favours people who invest a lot of time in socializing and politics rather than editing the encyclopedia.