I personally don't think the punishing difficulty curve was ever not in fashion with the gamers we're talking about. What happened was it fell out of fashion with the publishers, because they realized if they made the game easier, it appealed to a larger market.
What changed all this was kickstarter. All the games that developers still wanted to make, but couldn't find funding for because they weren't "modern" suddenly had a new method for publishing. FTL is a great example of that- it was an early kickstarter success and I doubt it would have been as good if it were published by, say, Ubisoft. What will be interesting is if we see a resurgence of hard games, just like the resurgence of point-and-click adventure games after Doublefine showed that people will still pay money for them.
What changed all this was kickstarter. All the games that developers still wanted to make, but couldn't find funding for because they weren't "modern" suddenly had a new method for publishing. FTL is a great example of that- it was an early kickstarter success and I doubt it would have been as good if it were published by, say, Ubisoft. What will be interesting is if we see a resurgence of hard games, just like the resurgence of point-and-click adventure games after Doublefine showed that people will still pay money for them.