Maybe because I’m a former copyeditor. But I’m incredibly Passionate about proper grammer and spelling because if you don’t have those things it can be very hard to understand sentences, your reader’s won’t want to waste they’re Time on you’re Book or you even if you think its good.
Editors and Agents too. They don’t like to read submissions from writer whom use inproper grammer or spelling even if you execute the story part good. Plenty of people say that its the storytelling that matters really but its not its a mix of Storytelling and Knowing how to write, that includes grammer and spelling and all that. Writers that submit they’re novels which are chalk full of mistakes frequently are rejected!
See Agent’s and editors’ don’t have a lot of time to waste deciphering bad-written novels; even if they may think the story is better than Harry Potter and Hunger Games and Twilight combined into one sparkling magical war book and even if they like you’re other ideas.
They just don’t want to waste there time making you’re Book understandable to readers. Those are you’re job.
Give yourself with a grammer book some help! Fine a astonishingly good text that can teach you the basic Principle’s of the English language and that you read on you’re own Time so that you can get better at the writing part. Also for spelling. It for some people is worser.
When it’s spelled good and has all the grammer right, you can submit a book that is your best work.
Just between you and I, learning the rules to the grammer isn’t the easiest thing but the good news is that its possible. Don’t loose hope!