always want to replace wipers? Is there a really good profit margin,
or do wipers truly need frequent replacement?

Throughout my driving history going back to 1963, auto techs have
recommended replacement frequently.

In this case, the dealer's mechanic recommends replacement even though
the vehicle has been driven a total of only 7,000 miles in four years
and spends most of its life in a shaded carport. Maybe the rubber
gets dry rot???