Actually, they don't. And that is another of Dr Morris' problems with the faith that is put into radiometric dating.
They don't ?
Somewhere among all those samples of uranium are surely some that started out not contaminated with those other elements, that show only 10 thousand years of decay. Surely somewhere there must be a set of potato peelers that didn't start with potatos already in their baskets. Where are they?
Is Dr. Morris declaring that that a fraction of a percentage of difference in the results should be considered to mean it's entirely possible and reasoable to assume there are actually several orders of magnitude of difference, or is that actual difference substantial enough to justify his concerns?
On exactly what evidence does the good Dr. ask us to believe these things?