Our first blender was one my parents bought in the '50s - a Waring.
My wife and I received an Oster as a wedding present in 1969 - it
still works fine (and, parts are still available), tho' the color is
Avocado (ugh). We bought a KitchenAid around 8 years ago, and the
clutch coupler failed on it recently, and lo' and behold, the part is
no longer available. The blender's in perfect condition otherwise,
now it's off to the trash because of the unavailability of the part.

So, here's my question: why so few blenders use the metal to metal
drive system as does Waring, Oster, and VitaMix. Is it a patent
question? One would think that since the patents on the Waring and
Oster designs should have expired long ago, this wouldn't be the
reason. Or, is it simply cost?

Sometimes I think it's better to find an older blender from the '50s,
'60s, or 70s on eBay that's in good shape rather than buying a new
one! Sure, the old one won't have sophisticated CPU control systems,
etc., but I really wonder about the reliability of ANY new small
appliance compared to those built much earlier.