Disagreement is healthy in matters scientific.
There can be no DISCOVERY without controversial ideas.
What is NOT healthy is the economic and career pressure being brought to bear on those with opinions which vary from the leadership. Enforced orthodoxy stifles creativity and works against DISCOVERY.
To the extent that scientific theories are "proven", it is by having knowledgeable people make a good faith effort to disprove them and fail. If a theory is true, efforts to contradict it will end up doing the opposite. Stifling those who would doubt with a theory doesn't prove the theory, but instead prevents any real proof. Not a proper course of action for anyone who really believes the theory in question.