That's because, as far as canon goes, his nickname is more likely "Hutch" :)
Wikia article you linked to has details on this (emphasis mine):
There is a controversy surrounding Jon Vander's nickname.
Cards of Star Wars Customizable Card Game and Star Wars Trading Card Game as well as an official action figure of him name him "Dutch", while the actual line of Gold Five in both Episode IV DVD subtitles and Star Wars: The Annotated Screenplays is spelled as "Hutch" (which is also what many fans claim to hear).
Until further clarification the exact spelling remains unclear.
The movie canon always trumps any other canons, so the subtitles of the movie are more canonical than trading card games or other merchandize. So are books (e.g. annotated screenplays)
Therefore, despite the last line of Wiki quote, the canonical spelling is "Hutch".