I think it must be down to "text talk". My daughter uses it when she talks to her friends online. I am always telling her to take the extra 2 seconds it takes to type the word properly.
The internet is becoming more and more widely available, so people who may not have English as their first language are likely to be joining DP.
I have to give you, and anyone one who speaks more than one language kudo's. I tried to learn German in school, and French and Spanish. I have a smattering of words from each but I just do not have the skill for it. As for the contributors where English is not their native language, I commend them for sticking with it. I will occasionally correct someones grammar, but only to be helpful and then only if they have asked for a review of some type.