The big companies don't care about genre. They don't care about games period, not one way nor the other. And when I say they don't care, I mean the suits couldn't tell you the difference between an rpg and an adventure game if you presented them with pictures of both. They really do not care. They didn't drop adventure and rpg because of the genre, they dropped them because of a downward trending line on a sales chart coupled with a downward line in market research interest amongst the target audience.
That's what the suits care about - sales data tables and market research. And you better believe they have decades of research in exacting detail. And while market research has its failings, especially in regards to something new, it is quite accurate in regards to things old and known. And those charts show adventure and hardcore rpg interest flagging. And it's not gotten any better today, either. Which is really bad since there are way more gamers than ever. For the suits, that illustrates a downwards trend in audience share, thus indicating a poor investment.
That's thirty years of data, and lots of rpg companies, with many different advertising techniques and some with sizable advertising budgets. And they all sold roughly the same amount. All of that advertising money, wasted. Because the mainstream rpg audience had moved on. And they still haven't come back.
The "mainstream CRPG audience", in case we're talking about the "second generation" fans of the late 90s and early 00s, never moved on. Bioware games still sell in the millions, which is what Baldur's Gate sold in the early 00s, and it's what their games have always sold. Bethesda has managed to increase their fan base massively, with Skyrim out-selling Call of Duty. By contrast to adventure games, which saw a string of bankruptcies and canceled titles followed by a period of silence, CRPGs have actually had it pretty well. Yeah, large segments of the Codex hate all the CRPGs released after Fallout, but that's not a fair assessment of the market.
Now, turn-based CRPGs did take a huge hit in the 90s when the industry was switching to real-time, but today they sell about as well as they did in the old days - ie upwards of a million copies, with multiple titles in the 500,000 range. Yes, their share of the pie - ie the total market for video games - is drastically smaller than before, but that's because the pie has gotten a lot bigger with the rise of the dudebros. It's no longer just nerds who play games, but nerds are still a large market.
As for the adventure game revival, this has been documented and reported in dozens of websites, so I'm not going to repeat it. The bottom line is that in the last few years we've seen a massive influx of new adventure games and many of them are selling quite well - ie in the millions, which is what led to the recent development of AAA titles such as Until Dawn, basically an adventure game with cinematic graphics.
What's more, Adventures don't actually have more creative settings, they just have a more diverse set of books to copy from, since their core audience aren't a bunch of LOTR/Star Wars epic nerds, with their audience having a slightly more wide-ranging taste.
Adventure games have more creative settings because they can get away with having no combat, but can still be set in settings with combat, ala King's Quest. CRPGs are, by and large, limited to settings with combat, either naturally occurring, else forced in ala Persona. It's very difficult to set a CRPG in, say, the modern world, because unless your protagonist is a solider in Iraq, there's very little room for constant tactical combat ie the basic gameplay of CRPGs.
Plus, indie Adventure games never actually went away, didn't actually need Kickstarter, since they were always more mainstream than rpgs and cost way less money and effort to make.
Adventure games were more popular than CRPGs during exactly one period, and that's the early 90s, when games such as Myst were out-selling all other games. During all other periods and on average, CRPGs have been as/more successful than adventure games.