Sure reading sms for americans is easy and doesn't take long time. But you don't take into account, that they don't teach SMS in english classes in foreign countries. When I first saw "Good4U" it was a complete mystery for me. It was quite a while before I learned to decipher it. I still badly stumble on some deeper SMS, even though I consider my english rather good. And there's many foreigners here, who know English as it's being taught in schools and on courses. For them such posts are just unreadable.
IMHO SMS should be treated as another foreign language, not equivalent to English. Just l1k3 y00 D0N'7 4((3P7 m3zz4g3z wr1773n 1n 1337, you should just ask "Could you translate that to english?" when facing SMS.