I disagree with everyone here except Jarpenguin. Philosophically we know that you should only judge people by what's on the inside: personality, intelligence and ethics. Grammar falls under none of those things.
Although grammar can be a reflection of stupidity it is not very often. Somewhat like how appearance is not a reflection of what's on the inside, thus we teach children to not judge people by it. Nearly every single one of my science teachers has poor grammar and spelling, but a good understanding of science.
I mean, when recruiting Staff, you'd have to take their grammar, spelling and punctuation into consideration. You'd much sooner choose an applicant who shows good knowledge of the English language, than an applicant who "typs lyk dis".
First of all, it depends on the job. If they are a newspaper editor certainly so. That is one of the skills that the job requires, such as a tennis player being physically fit. If they are a scientist applying to work for the large hadron collider I think their understanding of physics is thousands of times more important than their spelling, punctuation and grammar.
However if it is clear that their spelling, punctuation and grammar are bad as a result of the applicant not caring enough then I think that is quite an accurate reflection of their attitude towards the job. But remember in this case you the reason you are not giving them the interview is not because their grammar is bad but because it is clear that they are not willing to put the effort in to get the job, let alone be successful at it.
I find that the standard of the English language today is atrocious. When I was in elementary and middle school (about 20 years ago) I was required to learn not only spelling and grammar, but also sentence structure, and vocabulary. Now kids barely learn half of that, and on top of that, people are beginning to use 'txt speak' more and more often in everyday use.
The illiteracy rate in 1902 in the United Kingdom was 99.0%. Now it is 99.9%. You say that you learnt "not only spelling and grammar, but also sentence structure, and vocabulary" and that "Now kids barely learn half of that" when I can tell you from first hand experience, as someone who just finished secondary school that we are taught all of that regularly from the age of like 10 to now, where I am 16. And as for text speak I think what you are saying is completely wrong, that has been decreasing greatly in the last year or two due to the fact that it is no longer necessary as most text messages now have a waaaaaaaaaayyy longer character limit than they did not long ago.
I feel that I would without a doubt pick a person for a job who has a better command of English than someone who doesn't. Because if you cannot convey what you mean to say, then you cannot be understood by others. And it is precisely that reason why I feel that you can and should judge someone on their language skills.
What you are talking about here is literacy and the ability to speak English as opposed to knowing all the rules of spelling, grammar, punctuation and sentence structure. My grandmother never, ever uses any punctuation at all in her letters. Not a sign of a comma or a period. Despite that I have never, ever had any struggle with understanding what she is trying to communicate. peepl can write fonetically like dis and u can still understand wat they r trying 2 say very ezily