"There are more important things" isn't really an argument. No matter what value you are debating, there are always more important things. Value isn't an all-or-nothing thing. Just because something isn't the most important thing doesn't mean it has no value at all. No, it's not a crime to misspell or to define things the way you wish. No, it's not a moral failing. But the fact remains that if you want to be understood when you write, using the language properly is the best way. Assuming of course that being understood, not amusing yourself, is your primary goal in communication.