Mean traits in CAS

I sometimes play with Loner Sims. They don't get lonely when I want them to work on skills, etc. My favorite Loner Sim is married to another Loner and they're happy as little clams painting and writing novels all day and playing with their kitty.

Other than that, not really unless I'm doing a challenge or something. I did the Black Widow challenge, and the rules say to make her Evil, a Snob, and Romantic, so those are her traits. I made a Severus Snape Sim, and while I'm on the "likes Snape" side of the Internet debate I felt it was fair to say he could be Mean--and also a Genius. I've played the prebuilt Sims Vlad (Evil) and Malcolm Landgraab (Evil and a Snob). Etc. I also played the Oracle branch of the criminal career with my Master of Mischief Sim.

(Vlad is a good and indulgent father in my saves, because it's me, LOL. He can have layers! He has a more sociable wife in my save. Vlad gets his evil on when he's happy to see others unhappy... but not his family.)

I tried the Jealous trait once and found it incredibly frustrating. TENSE! my husband is speaking to someone who isn't me. TENSE! my husband isn't in the room, he might be speaking to someone who isn't me. SAD! my husband is speaking to someone who isn't me. UGH. Someone won herself a free retraiting! I've also played Maxis pre-mades with the hot-headed trait and find them irritating as well. Snob Sims, well, most of that I've experienced is Malcolm and Nancy Landgraab complaining that wahhhhh my mansion is "uninspiringly decorated" wahhh I'm BORED. My heart bleeds. 😉

It all depends on your play style. I generally do sweet happy families, loving couples (I used to only play same sex couples but I've branched out), and friends that crush their careers and spoil their pets, etc. (I only played Black Widow because it was out of character, and... she was a good parent to all those stepkids! and devoted to her Aunt! because it's me.) I'm a benevolent deity, for the most part, and mostly wholesome content.

However, there are other players who live to break up townie marriages, trap other Sims in their basement and force them to paint, put townies in a walled pool, and generally engage in that kind of antisocial behavior you mentioned. It's a single player game and they can do what they want to THEIR Sims... I dread the idea of multiplayer with those folks. 😉

I've also seen players say that Sims with no negative traits are "boring" and advocate that you use two slots for positive traits and one for a negative trait. I don't know, I generaly avoid hates children, hot headed, and jealous like the plague if I can help it, and my Sims do not marry noncommittal Sims or Sims that hate children.

All that to say: I don't like most of those traits, etiher! That said, I think you're the first person I've ever seen say that the Sims 4 is DARKER than previous incarnations of the game! I've heard a lot of the opposite criticism, that the Sims 4 is "too nice" and "candy coated" and "fluffy" compared to previous versions. (For the record, I LOVE FLUFF and find it relaxing, and if I feel like a challenge then there is always "testing cheats on, money 0" or lot challenges or an internet challenge...) So it's interesting that you would say that! 

Personally, I kind of feel like The Sims 4 can be a Young Adults going out clubbing every night simulator at times, and... meh.  😉 But there's still plenty of cute families and supernatural weirdness to keep me entertained!

Also, well. Mechanically, those traits:

• Mean - gets a happy buff from mean interactions.
• Hot Headed - gets a random angry buff sometimes
• Evil - is happy when others are sad, angry, uncomfortable, or otherwise unhappy
• Hates Children - gets tense or angry buffs around children... although not their own, as far as I can tell from the one I played for a storyline
• Loner - gets tense around strangers, is fine with actual friends, social need decays slower
• Noncommittal - is sometimes tense about commitment, becomes happy when they quit their job or divorce
• Jealous - gets tense, sad, etc. over their partner talking to other people, is sad to see other couples if single
• Snob - gets a bored buff in a "normal" environment, a happy buff in a nicely decorated environment, and a confident buff around other snobs.
• Unflirty - very uptight about romance in public but fine in private

So, even though I don't necessarily LIKE some of those traits, they're not all the same thing. I think it just feels that way because of the Mean Sims Bug, which... I don't have because I've modded it out.

My favourite of this list is the Hates Children, but I rather would I call it childfree. I use it because I don’t want to see the want/whim to have a child or try for baby for my sim. If I use this trait, I never get this wants (I am not sure if this is a vanilla behaviour because I only play modded with wants/whims).  

As @xochiquetzl_xkvn say, it gives enough player which use these traits and want drama, more drama as I like. Just because you don’t like it or use it, it doesn’t mean that not enough player uses these traits. As example, I find family/realistic gameplay extreme boring, and my heart goes up if we get occult gameplay, because this is my kind of gameplay.

I think each player should play the game as it wants, and yes, I would love it when player could toggle on and off more settings (as: Occults off, stealing from kleptomaniac/recycling trait off) More traits help with it, self if you don’t want to use these traits it gives enough player which want to use it. For myself I just mod the traits so, that’s suits my gameplay.

Oh yeah, kleptomaniacs. Thank you for reminding me, @daikoyu!

I play rotationally, and have found:

Actually playing the kleptomaniac: a blast!

Having your kleptomaniac friend over: GIVE ME BACK MY SOFA!

(Okay, I find the tense buff from not stealing though annoying, too.)

I tend to reserve sims with those traits for townies especially those of the super natural variety, be they brooding loner vampires or maniacal aliens. Their presence spices things up a bit in the absence of burglars (when I do not wish to make use of a mod like Extreme Violence that might increase the already absurdly high sim attrition rate when Neighborhood Stories are left active).