Geez, aggressive much? The topic of where reloading saves lies on the exploit spectrum doesn't even matter when there exist both a history backtrack function and a hardcore no-reload option in the game to allow the player to choose how they want to play, the point is just that the stimulant dealer does not have the baseline constraints of action time cost or daily limits that are applied to all other actions in the game that ordinarily would prevent exploitation of this ease and magnitude.
Usually, even if you reload the game until you succeed at something, success costs some kind of resource. Grinding skulduggery at lower level by spamming locked doors, for instance, takes time and gives Crime. Both talking to and stealing from the dealer are unlimited free actions, and the latter can grant XP, making it rife for abuse and a likely oversight. And oversights typically need to be fixed.
Additionally I'm perplexed you're going on about "making the game harder" when there is no conceivable reason anyone "playing fair" would need to pickpocket 90 stimulants. Having to spend time or only being able to filch one stimulant per day over the competition's three-week span would hardly impact gameplay.