Objectively speaking, BvS was the only film that's arguably "Dark and Edgy". On the other hand it was more of a Batman film more than anything else. But even then I'd argue BvS was more straight faced than necessarily "Dark". A Dark superhero film to me is something like The Crow and Blade. I think DCU can differentiate themselves with a tone that's serious about itself. That doesn't necessarily means dark.
If anything DC's issue is that the base is fragmented, in addition to them having too many separate universes with wonky continuity. There's been no stability due to behind the scenes politics. Not to mention again the broken fandom.
Man of Steel had
-Someone questioning whether Clark should've let a bus full of children die
-Purposefully invoked 9/11 imagery in city destruction scenes
-Had a hero who spent a majority of the movie brooding, sad and moping.
-Had little to no levity in it
It seems to me like they were trying to be darker/edgier. Funny to say, but darkness isn't a black or white thing. Sure I'm not saying MoS is dark on the level of The Crow, Joker, or even Logan. But clearly it was made with the intentions of being dark and edgy rather than just serious. And reportedly that's what they said they were going for:
Man of Steel to be 'Edgy' Like The Dark Knight. You can make a serious movie that isn't necessarily dark. For example, I don't even consider TDKS or some of the Craig Bond films as "dark." I would just call those more serious.
And I'm counting Suicide Squad 2016 as an attempt to be dark because if you remember Ayer's original take and even the initial marketing showed it as being dark and edgy. They only changed it to being DC's answer to GotG after BvS's reception with audiences went left. They clearly greenlit it to be a darker movie when initially shooting and Ayer along with others have said as much.
So even if you take out MoS, 2/3 of their first 3 movies were made with the intention of being dark. That's clearly what they were going for with the DCEU from 2012-2016.
"Straight laced" is more how I'd describe Villaneuve's blockbusters like Blade Runner 2049 or Dune. Not really what I'd call the first 3 installments of the DCEU.
But honestly I don't really care about the terminology. Whatever you want to call it. Straight laced, dark, edgy, mature, whatever. Cool. I don't really care to discuss that particular point further as I'm not tryna get hung up on that.
My point is that the DCEU tried to hang their hat on, or have their differentiator be, something that isn't necessarily commercially viable for big budget blockbuster movies or at least that hadn't been commercially viable in a while. And that was a bad decision.
I agree and would've loved/would love for DCEU movies to be more serious to MCU's "fun" and "bright" takes, while still having an element of fun to them. I would also like MCU movies to be more serious while still being fun, but that's another thread.
Kinda like in 2008. You had the serious TDK that still was fun. But then you had the fun but still serious take with Iron Man. That's great. DC being more in tone to something like Mission Impossible Fallout sounds awesome to me with the MCU doing their thing. But DC kinda screwed themselves there.
They thought serious/dark meant to completely shying away humor and making movies for "adults" because I guess they thought adults don't like humor and just like brooding and level 1 philosophy. Which was just odd thinking. That's the main point of what you quoted.
Why did they have this thinking? Idk. There are plenty of serious or dark movies that have a good amount of fun and levity in them. Even the pretty bleak movie Logan (or even using The Crow example) had levity, likable characters, and heart amongst the futility, violence, weariness, and darker elements.
Semi TL; DR: Straight laced, dark, etc. whatever you want to call it; DC/WB wanted their differentiator to be something that wasn't commercially appealing. And the lack of appeal can be seen in the critical or commercial results for their first 3 movies. Stumbling out the gate like that didn't help them at all and left them without a proper identity which they are still struggling with finding today.
