I've been a bit horrified in the recent thread started by
tethered, to see so many saying "spelling doesn't matter as long as you can understand it", "spelling doesn't matter for scientists" or even "it's rude to correct people's spelling".
The fact is, writing doesn't only convey the information we want it to, it also conveys an impression of the writer. All my students, when they leave, will want jobs (well, OK, not the delightful Hungarian lad who never did a stroke of work and whose millionaire aunt left him a fortune just before his finals!). They will need to fill in job application forms and write CVs. And if the prospective employer sees a perfectly spelled CV next to a semi-literate one, I know whom he will hire. There was a businessman in my home town who hired school leavers each year, and who required all applications to be addressed to the Personnel Manager. There wasn't one; they all went to him, but he was making life easier for himself, because every envelope addressed to the Personal Manger, the Personelle Manidger or any other variant was simply binned unopened. His reasoning? He didn't want employees making his company look bad by writing ill-spelled letters to his clients. And yes, they might have been good employees in other ways, but since there were plenty like that who could spell, why should he look outside their ranks?
I also recall a bunch of students who wrote a letter to our local evening paper about some issue. The editor inserted beneath the letter: "This letter has been printed exactly as received". The point being, of course, that it was badly spelled and punctuated. He was telling his readers: look, here's these people call themselves students, think they're brighter than us, and they can't even spell! Essentially he was suggesting they didn't need to take the case in the letter seriously, because of this.
Whether one agrees with him is mostly irrelevant; the point is that students who don't learn to express themselves in an educated manner do themselves less than justice in the job market and life generally, and I think it's part of my job to make them aware of that.