I've been doing some research - I can't call it a poll or even in-depth research - on how readers, critiquers (if thats not a word it should be), contest judges and possibly instructors weigh various aspects of writing. I have surmised that the things rated most important are basic grammar and spelling. Almost no one will even read a story (book, essay, blog) that is hard to read simply because it is poorly written in terms of proper punctuation, paragraphs, and sentence structure.
This could be seen as slightly unfair, because someone's lack of rudimentary english skills doesn't mean they don't have a great story to tell or fabulously developed characters, etc. The good news is that proper writing can be learned. While some people say -and others disagree - that various writing skills can be learned, grammer and spelling have set rules. And if, for whatever reason, a writer who may be gifted in other areas of writing cannot master them, there are editors and mentors and critique buddies.
There is no excuse to have a piece of work that is written badly, even if you have to rely on someone else for help with things like punctuation and paragraph format. If you have a great story, facinating characters, unique setting, enticing premise, whatever, it is worth learning how to write correctly or have someone, friend or professional, correct your work.