They don’t do the same with EC2.
I don't think this was a cynical marketing ploy designed from the top down either, it was a very natural thing for the company to be customer obsessed and trying to do right by them.
It's trying to do right by the legal and finance departments, not by the customers. Going after someone for anything less than a mid to high five figure AWS bill is never worth it because the legal costs are astronomical, the defendant probably can't pay in the end, and the cost of defending will drain the customer of any more resources that could have been spent on the cloud.
It's the cost of doing business. The choice is between trying to bleed a rock or a safe bet that LTV will be higher than the marginal cost.