Methods like get_/set_ do not necessarilly correspond to any actual member variable of an object. Making FETCH and STORE procedures that handle every possible method call would mean nested if statements or a dispatch table for all the exceptions, saying something like "if they tried to set the shnizzle property, go run some special method." Or worse, a bunch of in-line code for every exception in one gigantic method. It's far less practical than simply writing method calls in the first place.