<p>Because it stifles the exploration of free ideas that may be contrary to the legitimacy of the ideas of (whatever group holds intellectual authority).</p>
<p>For example, the status quo assumes that genetic differences in intelligence are insignificant when it comes to social policy. yet, there is plenty of reason to suspect that this is not the case - that there are differences in intelligence between different races (at least this is what the data supports at this moment).</p>
<p>And it’s wrecked the careers of some (see both larry summers and james d. watson being forced to resign over his comments)</p>