Yes, it is true, that good spelling really matters.At leat, I am very strict in this regard. I can hardly imagine a scrip full of spelling mistakes. Frankly speaking, I got this habit after having a great scolding from my teacher ,when I was at the age of 5. My scripts used to be so full of spelling mistakes.
But, now, I hardly do this, and I too dislike scripts full of spelling mistakes, because, it helps the reader to have a quick look, as well.