8mm slice thickness isn't particularly at odds with what is commonly done on commercial machines, though usually there is a second transverse scan (which can't be readily fused due to patient movement).
But even if it were, plenty of interesting structures are many centimeters in size, a thousand fold decrease in costs from eliminating cryogenic / high power magnets could be very useful.
the structures are many centimeters, but I assume that the sort of anomalies you'd be looking for in a clinical scan aren't going to be that large.
if you had a fracture/tumor/damage-of-some-type that's small enough to fit between those slices and you didn't get the slices lined up just right the scan would miss it, no?