Your definition appeals to tools and technological limitations, smalltalk had this notion that anything is editable, including the IDE itself and the (running!)

Your definition appeals to tools and technological limitations, smalltalk had this notion that anything is editable, including the IDE itself and the (running!) programs. Your definition + a smalltalk IDE would imply that a running program is text. Furthermore, the abilities of the message reciever factor into this as well : web pages are editable, but somewhat non-trivially. So the combination of tooling and abilities could be used to argue that everything is text: for a graphics artist with even a paint instance running, a picture is the epitome of human readability and editabiliy, while chess sounds like a gibberish unicode file opened with a wrong encoding. That doesn't mean your definition is useless, its an interesting take to draw the lines between media along editabiliy, but I wouldn't call that a definition of text. It would exclude and include all the wrong things. One is really starting to believe Wittgenstein that all disagreements boil down to definitions.