Unix programs are generally designed to work with text as it's a universal interface. Of course, there are several utilities that do indeed operate on binary objects (such as object and executable files); we aren't referring to them here. The point is this: Unix programs are designed to work on text as it simplifies the design and architecture of the program.

A common example: an application, on startup, parses a configuration file. The configuration file could be formatted as a binary blob. On the other hand, having it as a plain text file renders it easily readable (invaluable!) and therefore easier to understand and maintain. One might argue that parsing binary would be faster. Perhaps to some extent this is so, but consider the following:

• With modern hardware, the difference is probably not significant
• A standardized plain text format (such as XML) would have optimized code to parse it, yielding both benefits

Remember, simplicity is key!