Yes it's a case for entropy.

>Their natural state is to be tangled. We impose order on them by making them straight.

Even more than this, the "why" can be explained with probability. There are thousands, millions, maybe infinite different tangled states a cord can be in, and exactly one non tangled state. Being tangled is the "natural state" simply because it's by far the most likely state.

Every time you put the cord in your pocket and scrunch it around, you're picking another random configuration. Since "untangled" is vanishingly unlikely when picking randomly from all possible configurations, it "spontaneously" comes out tangled ~every time.