I can't speak for
@Aldarc, but I can explain why it seems arbitrary to me.
Aldarc, I and some other posters have all described RPG systems in which various abilities are
explicitly described as establishing exceptions to the general rule that a player decides what a character will think or do. Not all of them are about imposing "conditions" (eg that terminology has no real meaning in Prince Valiant) but some are (eg in Buring Wheel,
hesitation is analogous to a D&D "condition"; in Cortex+ Heroic having a certain degree of stress or complication is analogous to a D&D "condition"; in 4e D&D being stunned by terror at the roar of a Tyrant Fang Drake or recoiling in horror at the horrific visage of a Deathlock Wight is
literally a D&D "condition").
Not all of them involve activating "special abilities" but some do: eg I've already posted multiple times upthread about how, in our Prince Valiant game, Lady Lorette of Lothian - as a game entity - carried with her the Incite Lust special effect, which I as GM used on Sir Morgath when the latter was carrying Lorette in his arms having rescued her from her pursuers.
So when playing these games a player is
buying into such exceptions. These books don't conceal this. The MHRP rulebook has a full-page discussion, aimed at players, with advice about how to handle having Emotional or Mental stress, or social/influence type complications, inflicted on your PC. The Burning Wheel rulebook is replete with discussions about the prospect of your character changing through play, and identifies that as one of the most significant aspects of the system. Apocalypse World has a complex analysis of how its Seduce/Manipulate move works, with multiple worked examples. Prince Valiant has a GM-oriented discussion of how Incite Lust is expected to work, and that it can be cruel to a player and hence needs a degree of careful handling.
Yet upthread you've said that you can't imagine yourself enjoying these systems, although they seem to tick the boxes that you're now pointing to. That's where the impression of arbitrariness comes from.
Upthread I posted the following:
Nothing since I posted that has made me revise my conjecture about what is going on: that it's about authorial control over the character/personality of the PC.
Because, as I said, these other factors you're pointing to are all present in the systems that you're saying you don't like.