Players who won't think to be funny without mechanical encouragement, sure, you can't leave it to them to be whimsical. But if you play with players who don't need mechanical encouragement, then they will be funny with or without it, read the context of the situation more accurately, and know the kind of behavior that entertains the group better than an author who's never met them will. For those reasons I find rules-whimsy less effective overall, and therefore not as important.
I think that this argument is a bit of a furphy, as far as RPG tables in general are concerned, but it may be fine for your particular group.
If the rules and setting provide props, not necessarily for humour but for roleplaying of any sort, then more of that will happen. It's just the way it is. Yes, you can roleplay over a pure combat engine, but I guarantee that you'll see less of it than if the system gives you rules and setting props to throw around, similarly to how actors can act on an empty stage without costumes may have more trouble getting into character than ones in the opposite environment.
Well, humor's essentially subjective. My wife, who laughs her head off at the latest rant of the Ezio Auditore-meets-Bertie Wooster rogue, or at the gesticulations that describe the hunting behavior of the rhinostirge, would just roll her eyes at the +2 Backbiter and say "Man, another stupid screw-the-players inclusion. Did a player eat the last nacho or something?"
To clarify, the humorous use of the Backbiter I had in mind isn't a "screw the players" use (although IMO that's a perfectly acceptable part of true D&D games when used in considered moderation*). To be specific, it's more a PC inspired way of being cruel to peasants through an impromptu equivalent of a gameshow, once they know what they have (but enough said about that). When you ditch items and monsters that might cause a setback or inconvenience, you simply throw to the winds much of the possibility of this kind of humour or drama.
I think there is a place for cursed items, and it's in the campaign of a trusted DM. I get the impression that AD&D trusted the DM as a sort of equal, like Gygax was speaking to you directly through the DMG as a sort of co-conspirator (as opposed to patronising you), which is a leap of faith that I think that game designers of RPGs simply have to make (given that a bad DM will screw up any RPG). Throwing away tools that a bad DM might misuse punishes
all DMs, and the game is worse for it.
She prefers conversational wit to slapstick, and conversational wit is not something game books often do very well. They can only dictate; you can't have a back-and-forth with them. So our fellow players are far more successful in that regard.
I debate that - the gamebook setting, rules-supported actions and writing style can set up the very mood of the table, the content of what is happening and the possibilities for conversational wit as a result. Nevermind genre, for that matter, although I'm quite prepared to accept that people can be witty in any RPG genre. It's just that the genre is likely to influence the players, if it's doing it's job, as are the rules.
No, there's no scripts in there, but there is a stage provided, and the mood of that stage is different from game to game. I'm very surprised that you're attempting to argue this, as I can't think of an angle where playing, say, Paranoia would not affect the dialogue content and style of wit engaged in, unless said wit is part of the group's in-jokes and individual personalities independent of the game being played.
*: The "player entitlement" meme that's crept into D&D culture would have the DM throw away one of the masks of drama almost entirely, and make the game the D&D equivalent of Ladders and Ladders rather than Snakes and Ladders. Plus, if you identify items before using them, there's a good chance you can catch such things...and there's always paying for a Remove Curse. No higher highs without lower lows, it's a rule of the emotions, and rarely do such items kill anyone unless they're artifacts. In short, I disagree with your wife in her opinion about cursed items, but acknowledge that her take on it would probably see support from the 4E design team.