because they are inaccurate.

well you'd get WIDELY varying results from an autorefractor.  they are
getting better, but still they are inaccurate and serve only as a
useful reference to a good manual refraction.

in some Asian countries they will sell you glasses based soley on a
autorefractor reading. bottome line is you'd end up with a lot of
glasses laying around that don't work very well.

I find it useful to think of it this way.  An autorefractor measures
the optics of the eye, and therefore what the eye sees.  The
subjective refraction measures what the patient sees, i.e. after brain
interpretation.

Why would you need something like that?
Every OD's has "machine" which measures
refraction automatically the name of   "machine" is "auto
refractor" (USA) or "auto refractometer"(some other countries)
The receptionist who worked yesterday in the grocery story push just
one button and device makes and prints the measurements (astigmatism,
refraction, average  ) . Also it measures parameters for contact
lenses.
Copy and paste - it is the  prescription.
If you are interesting you can ask about reading of the device.

Then the OD looks on that printed "receipt" and sticks the different
lenses.
Around +0.5 -0.5 of what the devise printed.
Another manipulation with one button devise.

Easier even  then your cell phone which has "menu".

I'm sure many of those places have such a machine.  It's often used for
brand new patients, those who have just had eye surgery and people who
temporarily can't see.  It gives the doctor a starting place for
testing.  Since they don't work well, no competent doctor would rely on
them for issuing a reliable prescription.  I've had one used on me
twice, both times after eye surgery.