That would be such a silly reason. Why not be consistent and promote "paying due attention" everywhere then? Why only this specific bit? By the same logic, why not limit viewing each question to one time, asking a question to one time per account, logging in to once a day, querying a search result to once per lifetime, disallow editing? Cuz you know, should've given more thought and paid more attention the first time around. Hey why not only support scrolling down? You don't need to scroll up, just pay attention the first time around.

@ShadowWizardIsSadAndAngry how does that make it different? Being public is a minor detail (doubt too many people care about others seeing what questions they've bookmarked), and you could always search with Ctrl+f.

@animuson why roll out a feature if it's half-baked? The aggregation was the entire reason I used bookmarks. I relied on it. I'll now have to go to each SE site one-by-one to migrate them elsewhere. Also, "for now." Your comment is over a year old, and aggregation is still unavailable.