Yes, if you work in a hobby store, you might see mostly gamers, but with online and other channels, the market is much larger than hobby stores, the game is a small part of the hobby, something to do with a collection of miiatures you've bought and painted, thats how GW has always seen it.
I collect a lot of different games, most of which I've not actually played. and miniature quality is the biggest factor to me, Infinity has come on leaps and bounds in the last few years, Spartan are the same, the difference between my two Terran fleets is massive, Guild Ball might just be my favorite models of the year so far and I've yet to see them mentioned.
Where GW have the advantage is being able to do all they do on a scale that means they can supply so many people, they make a product that appeals to a massive base of people, something other manufacturers can't manage. And to be fair, some of their stuff in the last few years has been stunning, the Imperial Knight is an amazing kit, the Mechanicus Tech Priest Dominus is creepy and intricate and a real joy to paint. Their ability to make kits in plastic really still is miles ahead of anyone else, only Wyrd come anywhere close and they're still just not quite there yet.
Do they make the best sculpts - probably not, no
Do they have the best plastic miniatures available to the most people - definitely.