To be fair I'd probably write a note to Amazon if my delivery guy just opened the front door and dropped the parcel inside, porch or otherwise.
Perhaps I'm sheltered or perhaps it's just not the done thing around here, but I certainly wouldn't consider it normal and would highly likely contact the retailer saying so.
Would I write a formal complaint in the OP's shoes? No, not if I didn't have the chance to challenge the delivery guy but the goods seemed unaffected and worked as they should, but I was always told to inspect the goods upon arrival and if unsatisfied with the state of them to to reject immediately, and they weren't given that opportunity. I assume there's no signature required with Amazon Logistics so that last point could be moot, but I'd still complain on the basis that the packaging was suspect.