Well, truthfully, beyond the 'knee exercise' & better fuel economy that manuals provide, the automatic *IS* more popular...something like 85% auto vs. 15% manual.
While I prefer a manual, the wife has 'bum' a knee so it's only autos now...she used to drive manuals all her life, so it's not that she doesn't know how to shift, but rather that she now physically can't.