Never ascribe to malice for people you don't know and for things it is easy to explain with incompetence. If someone is your manager for some time and you can

Never ascribe to malice for people you don't know and for things it is easy to explain with incompetence. If someone is your manager for some time and you can reasonably expect competence, that is different thing. If someone is self interested and his actions say so, this is malice, not just incompetence.