Jumping a turnstile and taking a physical, actually scarce resource is not comparable to duplicating a digital, artificially scarce resource.
The train requires ongoing maintenance and can only hold a finite amount of people. Taking the train seat for free takes away something from another person. Downloading media does not use any ongoing resources, and does not take anything away from another consumer.
Comparing the morality of physical goods to digital goods are not really a good comparison specifically because of the artificial scarcity brought on by making something digital to try to make it more expensive doesn't map to the real scarcity of physical goods.