Great topic, thanks @commodorerob

To address the main topic concerns of barriers to entry into Historical.  You already raised the issue of exclusivity in the GW approach and I think this engenders a natural prejudice toward Fantasy/SF to those gamers who have grown up with their entry via the GW route.  There is a clear level of exclusivity built in to these games and their sales and marketing.  GW is very successful and vital for the hobby as a mode of recruitment and it is often the initial contact that many new hobbyists had/have with figure gaming.  This means that GW product and the associated contexts (Fantasy/SF) are therefore the most acceptable and recognisable contexts for figure gaming.  Historical has been deliberately kept outside this clear brand image and that means there is no natural crossover point between the two.  Far from offering an unlimited series of points of entry (as you might assume the multiplicity of contexts offered by the whole of human military history might) it is in fact all equally off-putting and unfamiliar when compared to the complex understanding GW based hobbyists have of their own products and fluff contexts.

But is this changing?  I think it most definitely is and will continue to do so.

• Many ex-GW potentates are out there in the industry and they have an approach that is totally inclusive of Historical.  They have also brought gaming mechanics that are recognisable to GW gamers and make the transition to historical contexts much easier.
• It is much easier to access material to learn a new game as video content is available for most systems (thank you Let’s Play).
• Gamers are much more likely to have an increasingly varied approach to their hobby and even those who are settled with a context/system will be willing to try a new one.  There is always someone in a group who fancies a new game or rule set and this is often all the impetus needed.
• Skirmish level gaming with say ten minis a side makes committing to a new game very inexpensive in either money or time.  Games like Guild Ball are so close to GW context and very popular at clubs that they can easily draw players out of their GW-only bunker.  Once out there is no reason to go back to exclusivity again.
• Resale markets mean you can easily get rid of game materials you don’t like/want and pick up those you fancy trying, often without needing to actually paint anything.
• Gateway games.  The increasing relationship between the board and miniature gaming hobbies is seeing a cross fertilisation of ideas.  Miniature games are increasingly adopting boardgame mechanics and techniques and boardgames look at the visual experience of painted miniatures and want that in their games.  It is no surprise to me that many of the biggest Kickstarter tabletop games are the hybrid boardgame/miniature games like KD:M, Zombicide and the CMON games and Mythic and Monolith’s output.  The only ones outside this profile are the party games (Exploding Kittens, etc. and Gloomhaven which clearly has a certain retro chic).  At the moment they are mostly Fantasy/SF contexts but I don’t think it will be long before there is a big breakthrough game with a fully historical context.  GW are even encouraging this by producing their boardgame-ish big box games.  This can help loyalists to transfer to other contexts as the packaging and gaming experience of other companies wares are less un-familiar.

In summary I think that Historical will be increasingly familiar within the overall hobby and players will become less exclusive to game type or context as the market continues to develop.  Inclusive communities like BoW will obviously help and this will discourage the less tolerant attitudes pervasive elsewhere.