It can also make more sense to programmers who know GUIs all too well, and who prefer to keep their data-related variables/logic separate from their widget-specific variables/logic.

And some programmers have additional reasons, involving the use of arrays and hashes to structure the data (and the GUI) in a maintainable fashion. It really can be more sensible to clear a bunch of Entry widgets by iterating over a set of scalar strings -- e.g.:  $_="" for (@ary); -- rather than calling the "delete()" method on a bunch of widgets...