Yes they aren't psychic, and they will insist that since they are separate tickets there is no contract to provide a connection between the flights as they do with tickets on the same itinerary.

To be fair, now that I think about it, I've been in this situation only once (the other times my plane parked at a gate), so I can't comment further. But this is what was told to me.

I even posted a thread here about it and everyone, including folks ITT, basically said "I told you so."