Why has this part been failure prone for so long - some say since year 1988?

Does the electrical wiring in the solenoid fail by opening up, or shorting to ground?

Does the hydraulic valves the A & B solenoids push and/or pull on mechanically jam,
or does a steel valve stem break after so many cycles?

One Youtube video of this part on a Neon
claims that an internal, non-servceable gasket begins leaking large amounts of ATF
behind the sealed side door with 6 bolts that has the warning label:
“Do Not Remove or Shift Calibration will be Affected”

I did not notice ATF leaking from this part,
but perhaps it was,
and I was fooled from looking closely
by the ATF leaks further below from the stripped bolts of the trans pan?