Why were Piston Tail Rods dropped in latterday designs?

Chris Newman posed the question: “Why were piston tail rods dropped from latterday designs?”

Wardale responded as follows:

“Without a tail rod the weight of the piston is taken by its head or by the rings if these are of lipped type.  They were dropped because head and linear wear was found to be tolerable (by former standards) without them, and because the poor rod packings tended to leak.  But they were never done away with in, for example, German practice (they had much better packings!)”