square please challenge us a little

[Zojha]

So, yes. We need first change the mentality. And, most of all, stop with the Speedrun mentality. Then maybe we can get something interesting.

Good luck with that.

The desire to speedrun something comes from the fact that you have stopped running the content for the fun of it and instead only run it for the rewards, which also means it is now in competition with other pieces of content offering the same/similar rewards (Reward per time/effort efficiency comes into play here). This is caused by repetition of the content, or rather, the diminishing enjoyment of the content itself. You can see the opposite effect in PvP games - against all reward efficiency, people who stomp their opposition frequently prolong the game artificially in order to stomp them more, simply because they enjoy the stomping (And since this comes at the opposing team's expense, they'll have a guy going:"Surrender@20!", as they now no longer enjoy it and therefore want to end it ASAP).
At times, it's also because you have become so experienced with the content that speedrunning is the only way it can engage you - that's no different for puzzles. People have speedrun even games as expansive as Ocarina of Time and I wager those were people who already knew the game inside out.

This is different from the desire to keep content duration limited. The longer something takes, the more likely it is that unforeseen IRL events occur - it's primarily a casual desire and much akin to having frequent save spots/an anytime save feature. It shrinks the time block people have to dedicate for a certain piece of content. For reward efficiency, it doesn't matter if a content takes 20 minutes, 40 or 2 hours - you just multiply the rewards accordingly. I am willing to bet however that the shorter ones would still be preferred.
There's also the matter of expectation: If you are used to dungeons taking 25 minutes, that's what you will expect of dungeons and consequently, you'll be inclined to get into a dungeon if you only have half an hour of free time.

So yeah...I can only repeat:"Good luck". I don't see how you would be able to change the mentality.