Don't worry 'bout it Isaac.
Just shrug it off and avoid people like that.
They obviously need the shortboard image to stay cool and probably to be tough because they have insecurities about their own sexuality. Chances are they think you're stealing their coolness and feel embarrased, get angry and call you a fag.
Most importantly though, don't hate em just because they ride a double kick.
I know alot of people who ride shortboards who are equally as rad as longboarders.