He's making it work regardless of someone typing a command in color or bold or whatever. The alternative (and better way to show a new scripter, imo) is to use $strip(). It does make the script a little longer and may be slightly slower or faster (not noticeably), but it's a lot easier to understand for a new scripter.
Personally, I don't cater very often to people who try to type commands in color/bold/etc, but that's just me. By catering to them, you have fewer people asking why a command doesn't work. My thought has always been that users should learn that commands should always be typed in plain text (no color, bold, etc) rather than requiring scripts to slow themselves down (albeit not by much) just to cater to a few people. If all scripts were to require commands be typed in plain text, then everyone would learn it very quickly and there would be no need to cater to anyone. I know, I know... not a popular opinion.