Just to nitpick, guy and dude are not gender neutral, they just happened to be heavily used by the community in general, mostly because people assume users are men by default.
Even if we were talking about 'he', your link would be out of place. Calling out the use of a gendered default as bad is not in fact another point of view on whether it is the default.
For example, "Oh, I know a guy that knows X," "I know a guy that is a fan of X" or in a less positive manner "That guy just cut me off [on the freeway]!" (since you rarely see who it might be and their gender doesn't matter)
I could say "dude" as well, but sometimes dude might be too informal. I could reword it with a number of other pronouns, but it depends on context and whom one is talking to.