No, a complete meltdown wouldn't go through the core, the floor, and the earth. In a light-water reactor, the fuel-coolant interface (where the slag would drop in a complete meltdown) would significantly cool the slag and will not substantially breach the primary pressure boundary, or lead to the gross structural failure of the primary system or RPV, and the corium will reach the lower plenum with the lower plenum remaining intact. This is what happened at 3MI, which again, was a higher category of accident than this one.
As it is, since we're a couple of days past the scram event, almost all (though not all) of the highest-danger isotopes have already decayed away. That's where the heat originally was coming from, and why (I imagine) that they decided quickly to kill the fuel by dumping the seawater and boron in when the pumps failed. They took the side that they'd rather cause severely expensive damage to the fuel inside the core while keeping containment, rather than take their chances with a loss of containment early in the process when the higher-volatile isotopes would still be prevalent in the contaminants.
I don't think taking bribes is right, or that "everything is peachy". A meltdown is going to significantly raise rates for energy, cause a lot of capital to be spent rebuilding and repairing the site, and cause a stigma among people that something really dangerous happened. It's just not true.
Not that I think you're lying, but I haven't seen anyone publish a scenario where 30M people die from groundwater poisoning. Have you read that somewhere?
