Without cursed items you can definitely still craft jokes about PC sociopathy and how they can use deception and magic to abuse the crap out of hapless peasants, and those subjects will definitely still come up if that's what your group thinks is funny.
Oh come on, enough with the cheap shot, "you're low brow", psychobabble name-calling snootiness. If we were interested in exploring "sociopathy" we'd be playing something like V:tM (and that's not being fair to V:tM players, I object to your use of such terms when applied to your opponent in an argument rather than to insane criminals, IMO it's just not called for and trivialises a serious term in a shallow attempt to demonise someone).
And just for the record no imaginary peasants were hurt (it was just a joke, and you had to be there). Besides, I'd argue that evil PCs
can be harmless fun, and generally have very limited life expectancies due to the other PCs resenting being betrayed and stolen from, the wrong assassination attempt on a prominent NPC leading to repercussions etc. so good generally does triumph in the end.
Back on to a variation of the topic. As far as the Disneyfication of D&D goes, it's not even up to the times with that maneuver. Consider Knights of the Old Republic, Grand Theft Auto or other CRPGs where you get to play a bad guy, or innocents get caught in the crossfire. At your table, do you offer morally grey adventure hooks like that of a loan shark, mercenary or bounty hunter, or outright evil ones like assassination, unjustified sabotage or ill-intended espionage? It's easier to roleplay a good character when you are able to identify such shadiness for what it is, and reject such hooks (or even get sucked into one, realise too late who you're working for and to what end etc).
I suspect that this at least partially comes back to issues of trust. You can trust Bioware not to do anything vulgar with a Dark Side plot hook in KotOR, but not the general public at large, but take that away and it's gone from the game by default unless put back explicitly by players who overlook what the disneyfied rules suggest and notice it's absence. So RPGs are on something of the horns of a dilemma.
These elements can be part of a world just for depth, and not supporting them, in say, the PHB, DMG or MM for politically correct objectives is by default going to remove that depth. I realise that you are just arguing that they shouldn't be built into the rules, and that it's up to individual groups to decide for their inclusion, but I think this trivialises the grip that the books and rules have on the culture of D&D, and resultingly how it gets played. One of the things that attracts audiences of all ages - from teen up - to AD&D 1E is that it had this depth. And please don't argue that these elements haven't been intentionally removed from the scope of the game, as it is written and in terms of what the rules suggest.
The best examples I can think of are Monty Python quotes and puns: to some gamers, they're high comedy, to others, they're repetitious or lame beyond accounting.
They're also about 40 years old, and extremely tired, which make them very useful for pretending that all humour in games is tired. I mean, come on...