Why is it that in today's working world being able to write well and to use grammar correctly are so important?
It's vital that people be able to communicate clearly and succinctly in writing. With written communications, facial expressions and tones of voice are not present, so to ensure complete understanding on the part of the recipient, the writers must communicate their ideas correctly.
In addition, using sloppy grammar, unclear sentences, and incorrect spelling is insulting to the reader. It shows that the writer doesn't care to communicate appropriately.