What a Strange thing that people try to treat, manage, modify and manipulate human behavior without understanding human psychology. your opinion?

That is like treating the symptoms only. As every behaviour is only a consequence and a resonse to a stimulus within the environment. For a behaviour to be truly and well modified or 'treated', a knowledge of behaviour analysis is required. This will help re-direct either the stimulus or the response to the stimulus.

I don't know what is meant by "Human Psychology" here. This could be anything and everything. In any case, the only prerequisite I can think of is expertise and experience in applied behavior analysis is a must; before any serious attempt is made to treat, modify or shape human behavior. Behavior Analysis and expertise in it is essential; however there are other approaches also for treatment that often are combined to render better overall results.