I don't think it is a question of good guy or not, rather it's about honoring the contract. The moment you sign up for something you are entering a contract to pay. It's your obligation to do so. Now the other side can choose not to enforce that, but that doesn't make them a "good guy".

E.g. If you rented out an apartment but stayed at friend's place for a month, then is the landlord going to skip asking for rent for that month? No. Does that make him a bad guy? No. It's your responsibility to pay for rent. Same thing applies to car loans/leases/rentals, Newspaper subscriptions and Gym memberships. So, why should SaaS pricing be different? Granted an app can easily figure out if you haven't used their system that month, but then so could a gym.