One way to avoid the pitfalls of not knowing what a publisher likes to take on is to do a little digging. Research the types of books they like to publish, how many titles a year they put in print and even what types of authors they publish. But it only takes one. Just one publisher can turn your manuscript into a published book. Sure, it's easy to avoid submitting your work.
Failure keeps most writers skeptical and skittish.
Too afraid to send out their work. Having your work on someone else's table makes you feel vulnerable. But feelings have to be shelved when you submit your manuscript. It's the people who have a long-term desire to succeed who will become the next great author. Writing is just like any other craft.