As always XKCD sums this up nicely: https://xkcd.com/627/
With a user-friendly GUI, a web browser, and this "cheat sheet", GNUbies can solve many problems learning, tweaking, or fixing their system independently. If they install GNU/Linux and get presented with nothing but a blinking prompt, they need an experienced GNUser to talk them through every new thing they need to do. Thus, good GUI massively increases the reach of free code software, and empowers people to adopt it after reading about online, rather than being personally recruited and trained by an existing software freedom jedi.
