If most gamers want only a subset of what tabletop RPGs offer, then what do they offer to those truly interested in them- what does the audience actually want from the medium? To answer that, you have to know what the medium is and how it works.
The tabletop RPG medium takes the tabletop wargame medium of the mid-20th century, with its reliance on referees to issue rulings to cover emergent concerns at the table, to its maximum creativity. This is not entirely by design; originally, this was just a means to take the popular variant known as Braunstein into other applications, but once the early campaigns broke containment by the commercial release of Dungeons & Dragons, the expansion of the form into the hands of people not of that Upper Midwest wargame scene revealed that this new medium is defined by its liminality.
That's right, liminality. Because the medium sits at the point where it can easily slide to and from any specific activity that the characters could reasonably engage it, it sits beyond the scope of the focused games that do one specific gameplay form very well. This vital quality gets lost when mechanical complexity reaches critical mass.
The ideal tabletop RPG, as a commercial product, is as it was in the beginning: a slim booklet, packaged as part of a set and put in a box. Why? Because, for normies, "game" means "think in a box with all necessary parts within". Normies are part of your audience, so give them what they expect to find. (Remember that Clarity thing.)
The audience for tabletop RPGs want the liminality that defines the medium. That means that you can't focus too much on any one thing, aside from that which is so commonly done at the table that such specificity is required. Instead, you want your ruleset to give the Game Master enough information that he can just run his ass over to Infogalactic, TV Tropes, or whatever real-world info source he needs to consult (including sites like Wookiepedia) something and easily translate real-world language into something he can use to issue a ruling at the table. Embrace asymmetric rules knowledge; it adds to the quality of play experience. The GM needs to know; players don't.
This is why the enduring appeal of the older editions exists, and why trying to make tabletop RPGs something that they are not is a reliable way to sink the business. (Yes, the supplement treadmill is an example of Doing It WRONG!) As the design and publisher, your job is to make tools of creativity, put them in the hands of Game Masters, and let them make their own settings. You're the wholesaler, not the retailer; that's the GM's job.
Lose the desire to focus and embrace the glory of liminality. Or stop selling tabletop RPGs.