The last ten years the business paradigm was that people want simplicity and linearity and cutscenes, but just because the main bulk of the industry believe that, it doesn't mean it is true.
And perhaps 75% of the market does prefer this sort of game, so the industry focused on that, but kickstarter is showing the possibilities of serving the other 25% - including older gamers prepared to spend quite a bit on kickstarters etc.
I guess it could be worth a shot finding out whether or not some of that 75% estimate of yours would be "Ok" or at least interested enough to give a shot at something more
Neo X-COM shows that they are. I know it's not exactly on par with Codex standards, but a turn-based, squad-based tactical game did insanely well and was praised across media platforms, and is still played enough to warrant a full-fledged expansion. Meanwhile some obscure company makes an obscure square-dance successor to an old game and the shit sells like it was tits and coke (Grimrock).
There is no need for "finding out anymore." If the production values are there (as on X-COM and Grimrock), people are more than willing to try out a broad category of shit. Not the casual sportsguy playing FIFA and CoD only, of course, but you don't need him to turn a profit.