The DefaultTextMode is an SMO setting that specifies the default value for the TextMode property of all the database objects on the instance of SQL Server. The View object, for example, supports the TextMode property. The DefaultTextMode sets the default value of this property on the instance of SQL Server.
The TextMode property specifies whether header information is generated automatically for SMO database objects that have a Text property. In SMO, the View object requires you to specify the definition of the view by using a Transact-SQL statement in the Text property.