I'd venture that there are plenty of folks out there like me. I've been brewing 8-9 years - anywhere from 50-220 gallons a year, never joined a club, never took a class, never entered a competition - until this year! I still just use a 10 gallon SS Kettle - and brew either in the basement or on the back porch - so there's nothing fancy about my HB efforts. I have mostly made up all my own recipes (hence why I never know what style the brew might fit into), and seem to favor brown and red porter like concoctions. I and a friend started growing my own hops 2 years ago, and did some serious transplanting and expansion of the number of vines this spring.
So I am one of what I imagine is a pretty good # of homebrewers that is largely off the radar and unaccounted for.