I'd say the tolerance for slow-paced games is also much lower now. There is some truth to tolerance of frustration, but it really boils down to people just not wanting or being able to invest as deeply into an RPG as previous generations. So while I still play Icewind Dale and may have to try a boss battle 10 or more times before beating it (because I suck at RPGs ), that is not a type of scenario that is really going to fly today. Even Dark Souls isn't going to kill you that much, as that game is based around dying but then quickly developing a strategy based on your first mistakes. In general you aren't going to run into these insane-level challenges or many obstacles at all in today's RPGs, unless you're playing on a higher difficulty level or some weird obscure RPG like Elminage Gothic. And even at that Elminage removes a lot of the difficutly by allowing you to save anywhere.
This is just an observation, by the way, not a judgement.
Yeah this is a psychological trend that is not just about RPGs. In the era of instant gratification and massive availability of new content, people feels entitled of having all they want, and fast, then switch to something else. This has translated into all media in the entertainment industry, and videogames are not an exception. Back when we were kids and we had 3 games on our computer, we had to keep playing them until we beat them, or quit playing, because getting new games wasn't insta-magic like it is now. there was one new Ultima or one new M&M or Wizardry after many months, and until then you kept trying. Maybe if we had been given the option to, instead, play 637 new "freeish" RPGs each week, we would have never beaten some of those "long investment required" games out there.
I'm sorry to keep pissing on your well thought out and informative points, I must seem like such a nitpick artist, but... aren't all the kings of popamole crap gaming all the hour-munching time sinks that demand people play them for 1,000 hours, and that's before they start modding them...
Just a point to consider while you evaluate your next work of genius.
If you are denying nowadays people split their time among MORE games than they used to in the 80s-90s, you are delusional. I see it in my kids and their friends every day (16-19), they switch from one thing to the next every week. The fact some people spend a long time in a game doesn't prove anything, and isn't new either; I don't even want to imagine how long I played some games like MM3 back in the no-walkthrough era, or in playing gold box+dabbling with FRUA, but it must be insane, maaaany hundreds of hours. What is new is the hour counters, and profiles that show how much you have played.