We've all been told not to judge a book by it's cover. Personally I think that's a sound philosophy though most of us can't help it, and in fact, we tend to judge a lot of things by our first experience. If we go to a restaurant and the food is bad we usually don't go back. If we buy flowers somewhere and they don't last, we go to a different florist. If we meet someone and they're not too friendly we often don't give them a second chance.
As writers we often speak of the many hoops we have to jump through. I think we should be glad of those hoops. They give us lots of chances to get it right. We have the opportunity to have our work critiqued, beta read, we have people who don't judge our first attempt and tell us how to get it better. Same with our queries. Then we get to send it out to an agent. If they don't like it we adjust the query and try again with the next agent on our list. I know we all bemoan the fact that we only get one shot with each agent but that's not exactly true. There are revise and resubmits and conferences where we can visit with agents personally. I know we feel there's only one chance but the system has several steps to it. Steps that help us not be judged by our first efforts.