As an aside: I do a functional-limited trial rather than a time-limited trial precisely because 100% of the use of the software for 48 hours satisfies the need for 95% of my customers. "First year free" would wreck my business pretty comprehensively if folks took advantage of it.
I'm confused why you're using the word "compassion" at all, and coaching your argument in terms of how "compassionate" banks will be in their terms next time around.
Banks exist to make money, the terms they offer are a balance of how much risk they are willing to take, how much return they can earn, government regulation, and competition.
The OP does not owe the banks anything other than the terms of his contract, and the terms say that if he doesn't pay his mortgage he'll lose his house.
If you could remove the users ability to use the software when you refunded them $30, like the mortgage lender can when the homeowner stops living in it, you'd probably still be in business even with your clause.
On the other hand, if all of your users bought your software, thought it sucked and never used it again, and then got their refund, well, you should probably be out of business.
The OP's situation is not analogous. He is not free riding.
Edit: On the other hand, the year's worth of free rent before being evicted is to me a bit morally shady.