I know the issue. But since DME isn't asking everyone, obviously our luggage becomes our responsibility. I googled and looked at one random result, and while Jet Blue says to contact them within 4 hours it doesn't go on to say "or when we find your bag we'll just sell it immediately".
DH has been on some long, connecting, flights, where a bag disappeared on the first leg. It's been far longer than 4 hours from it disappearing (known in retrospect, once they locate it and see where it went awry) when he knew it was gone. Yet each time they (Delta, the only one so far that this has happened with) got it to him within 24 hours.
If DME isn't asking the question and any given person is too nervous to deal with the possibility that they'll be calling, for example, 6 hours after the flight landed, that given person shouldn't be using a luggage delivery service. Most definitely.
The other thing I was thinking of as I posted the feeling that it's my responsibility is that it would be possible for a bag to slip through DME's tracking system (I've read they scan bags too?) and be delivered but not show as such to them. If a bag can slip through being tracked by the airline, surely DME can miss one too. So they start a lost bag claim, meanwhile the person has it. Just seems to be a better idea that the traveler is involved.
Obviously the BEST thing to happen would be for the tracking systems to become totally transparent, so we can actually follow our bags along their way. For MCO as a "host" to this company, the airlines whose paying guests use these services, and Bags/DME to become true partners instead of adversaries pointing fingers. That's the best solution.