The thing that keeps most people--including most gamers--away from tabletop RPGs is that a proper tabletop RPG comes "incomplete" by common eyes. You get a ruleset, and that includes toys (in the form of mechanics), but the user supples the rest of the game- not the publisher. In practice, this means the Game Master supplying everything but the players' characters. Setting and Campaign are not required purchases, even if many (including publishers) want to believe so.
The problem is that most people--I dare say the majority--do not, and will not, work for their entertainment. They get mad when they can't just show up and play the game, and mad people get frustrated. Frustrated people stop doing the things that frustrate them right quick, revealing by their actions their preference for ready-to-go entertainment.
This is one of the big pushes by publishers (such as those behind TORG) to make tabletop RPGs something that folks can play cold (no preparation) and stupid (no prior or outside knowledge), just like you can with boardgames, cardgames, and other competing tabletop gaming options. (Nevermind videogames, which do ALL of that even better.) The problem is that those seeking to make that happen do it wrong by getting away from how tabletop RPGs work: describe situation, as "What do you do?", resolve actions, update situation, repeat.
That fundamental feedback loop is what drives a tabletop RPG. You need very few rules to make that happen, and that's why the earliest TRPGs are still the best ones around; the known weakness (the Game Master, when ignorant and inexperienced) can be worked around easily simply by not being a punk bitch and instead be the responsible adult most people (including gamers) are.
It is at that simple level that makes the genre most friendly to people, since all they need to do is consider how their man would act in the situations the game's events create and then act accordingly when asked "What do you do?" Let the Game Master handle those rules, and make his rulings; for players, all they need to know is what their man can do and what tools he's got to work with. Pushing more mechanics on to the players is contrary to the power of the genre.
(Yes, this means that hybrids like TORG do miss the point of RPGs. It's not the first time, and won't be the last.)
The way to get people on board is to sit them down with something already familiar to them, make creating a viable character easy and fast (which is why I prefer Character Templates, as early editions of Shadowrun as well as West End's RPGs were well-known for; pick one, personalize, and GO!), and what mechanics they do use are simple and easily-remembered ("Always roll high." was one of the smarter d20 System axioms for this reason.) The rest is all about that feedback loop.
I harp on the loop for a reason: all by itself, that loop will drive all of the gameplay you will ever want or need. "Here's the situation. What do you do?" is so simple, yet so powerful, that you never need to touch a single fucking narrative fiction trope to produce powerful, satisfying experiences of any sort. The catch? They may not be the ones you expect; what comes emergently from the results of those actions can be anything plausible in that moment, and I do mean ANYTHING. Being open to that is critical, and if you can make peace with that fundamental uncertainty--that core of chaos--then you get this genre of game and can work miracles with nothing more than a rubric for making rulings, two worn dice retired from a craps table, and some way to keep notes.
You don't need a publisher to sell you a setting, because you can create it as you play. You don't need a publisher to sell you a campaign, because your players will create it emergently as they run that feedback loop. Neither may be what you expected, but they will be what your groups' actions result in when you sit down to play. Miniatures, maps, fat tomes of mechanics and rules- all completely optional and not at all required. Once common people experience this in action, they break from thinking of TRPGs as "incomplete", see how complete it really is, and see how they are separate and distinct from other forms of RPGs (and other forms of game).