As an aside Games Workshop refer to their games (Warhammer, LotR miniatures, etc) as the Games Workshop Hobby .
I really don't think that the semantics of it being a role-playing game rather than hobby puts people off, its more the trappings of dice, lots of rules, and the stereotypical image of gamers that does it.
Role-playing turns up a lot on training courses in the government and corporate sectors so its hardly a unknown concept to the general population, but that is with some rules set by the scenario presented rather than three fat books.
To really grow RPGs I think a simple easy to use version of D&D is whats really required for newbies. Looking at the three hefty manuals and dense numbers of rules has to be a turn off for a non-gamer, after all games like chess, chequers, or card games don't have 300 pages of rules to know before a newbie starts.