While a place is certainly within their rights to stick to the letter of their policy, and there has to be a line somewhere, being petty over a couple days is not necessarily in their best interest. It would seem reasonable to have an unwritten grace period they can allow at their discretion. As someone said, they will probably lose that customer and their recommendation forever, and maybe wind up with some bad attention. Plus limits like 180 days are somewhat arbitrary, it's a round number and not (usually) something magic.
Another thing about cancellations - would they have sold the room or whatever to someone else? Is there an actual loss to them other than a little administrative work? I know this can especially be an issue for small places in more remote spots, where people tend to book ahead and they're less likely to have people wanting to come at the last minute. But when a place is fully booked with people chomping at the bit to get in, good chance they will fill the spot 6 months out. And if it's not heavily booked, it's unlikely the person cancelling had prevented someone else from booking anyway.