A Tangent – or, A Rhetorical Question About Insurance

If you insure something (oh, let’s say a house) for a certain amount, and you pay for that insurance, but then that thing you’ve insured gets destroyed, how is it that those insurance companies only have to pay 50% (to be generous) of the amount for which you paid to insure it? How is that legal? And who is it that re-defines things so they fit thru those loopholes?! (I wonder if insurance companies hire linguists or something.)