Well yeah it's not the OP's fault but the guest's fault in general. You as well as I understand how people make things change for other people. The OP knew the 2 hour window, liked that it gave them the flexibility, but then called it petty when they were then held to that standard. That in itself is probably not going to win many posters on one's side.
It's not just merely a switch from one expensive place to another. In what realm does that honestly make sense to just use that as one's logic for when a generic cancellation policy previously applied generally should now just be considered based on an ever-changing price tag? Would you think that's fair that you were held to a different policy because you didn't spent X amount but someone else did? So you spent $50 but someone else spent $70 and so you should get a different policy than them? I don't for one minute think you would be okay with that.
You can argue all day long about dining alerts but from what we know the OP themselves said they checked
MDE. Even so the OP advises they were aware of the new policy but thought they could (however innocent) and even so dining alerts are what type of excuse for controlling one's own impulse?
As for your last line absolutely 100% yes it would hurt because if you've worked with customer service you know 100% it's never just that one person. We all know that one because in our lifetime we've all probably at least once asked to be that exception lol.