This doesn't surprise me at all.
The movie has absolutely no appeal for non-cinephiles. The movies marketing is based entirely on borrowed trust.
Otherwise it's just "Hey look Tom Cruise is wearing a bunch of make up and holding a shovel in a weird way. Want to buy a ticket?"
Tom Cruise's DIGGER pre-sales keep going down and may bomb even harder than we projected days ago.
How bad? It might even miss the double digits. Right now, it’s tracking to be Warner Bros biggest bomb of the decade with a $9M-$12M debut on a $180M budget.