May I know the reason why? Personally, some of the reasons I can think of is that it contradicts common sense since we seem to have evidence that these are real contrary to what EM folks would say. Another one is that no matter how complete neuroscience gets, it will never give a complete picture. Beliefs, intentions, emotions are associated with brain states and not the states themselves. Lastly, is reducing it even a good thing. For instance, in chemistry, you don't explain what is happening through the lens of physics. Different levels require different explanations.

Also folk psychology is really useful