New authors always have huge goals in mind. They believe that first book will be enough for them to quit their day job, by a mansion or two in the Hamptons and spend their days writing like the authors we see in the movies. New authors have to remember one thing. They are NEW. They have no track record. They likely have no following in authors. Even if they are self-published, their following or the reviews they have on Amazon mean diddly squat.
When an editor signs an author, they are taking a gamble. They are putting out an advance to that author, taking a chance and hoping the author will sell and hit it out of the part. Can they see the future? No! None of us can. We are just keeping our fingers crossed.
So, with that said, you are now with an agent who is also taking a risk on you. They are doing their best to find you a deal. They, like you, know where they would love to see your story, but they also have a realistic view that, because you are new, that ideal editor may not occur on the first book. Still, they try.
But what happens when they do make that sale to an editor. It may not be that dream editor, but hey, we got a sale! We celebrate. Remember, agents are not going to put you with someone they do not trust. Everyone is on your side, and everyone wants you to do well.
Does this mean you whine about it? No. Celebrate that success and make those other editors wish they had signed you. Work on that next book an make it sell.