Really? They didn't receive "good education", so makes it somehow OK to write like preschooler? They would need to receive education deliberately worsening their learning skill for it to be understandable. Capitalization of first letter in sentence isn't difficult concept to grasp, neither is using periods at the end.
Your ignorance is not surprising. I am from India where our education system is multi-lingual. As a developing country many of our schools (and even colleges) are poorly funded. Many students in these small and underfunded schools (especially in rural and urban poor areas) are taught in their local language. And while English and another non-native language (or another foreign language like French in some of the better schools) are also taught in these non-english medium schools, the focus is often only on basic reading and writing skills. This is partly why some indians struggle with the language. Those who can speak it fluently often have the advantage of a better education (and more importantly educated parents who emphasised on reading books and speaking fluently, and a social network conversant in the english language). I've seen many a good student struggling in college and workplaces because of the language barrier.