A lot of fiction markets make much of the requirement that the protagonist have a driving goal. The main character must be proactive, not reactive. Some even require this motivation to show up in the first page or two.
To a certain extent, this makes sense. I think it's one of the most common mistakes newbie writers make: they create a main character who is solely reactive, fighting against misfortune without agency of their own. Giving the main character motivation forces a writer to think about who the character was before the opening lines. In the fantasy field, I'm sure the popularity of the Chosen One trope is partly due to the ease of it. The main character doesn't even have to do anything: the villain is after them because the prophecy says so, and of course, then it becomes self-fulfilling.
But for me, I think this strong motivation isn't always necessary. I enjoy characters who are finding themselves, who don't yet quite know what they want - characters for whom this very uncertainty is their prime motivation. I find there's something very powerful in a character blossoming to discover purpose, or even just the hope of it ... which, of course, fits very nicely into the open-ended, "yes but ..." kind of story conclusion I like to write.
Certainly, I'm not saying that characters can be aimless. Smaller goals, or an immediate situation to react, can lead into the real problem: characters wondering where they should go, who they are. I find that discovery makes for a uniquely satisfying conclusion ... because can't we all empathize with that feeling, that uncertainty? And is there anything better to live vicariously than that discovery of purpose?
So while I understand the editorial concern here, I wish they'd relax this standard a bit. Sometimes, there's a wonderful story in the question mark.