The question is both interesting and offending, but ignoring the racist connotation and focusing on the theme might require an in-dept study and analysis. Without any such references as I do not have a linguistic background, I would try to answer your question based on my experience.
First before I proceed, certain factual errors needs to be corrected.
Many users from India: If you perform an informal census of the Stack Exchange members, it would be a revealing encounter for you that the next most populous nation participating in Stack Exchange after the native English speaking nations is India.
Is this a reflection of how English is taught in India, a similarity to Hindi: India has a diverse education system and languages. Considering this fact, you cannot blame the education system in India for sloppy English usage. There are some notable Indian writers, educationist and scholars who had their basic English education from India.
What could be the reason for sloppy English?
- English is not the mother tongue of most of the Indian population.
- Not all the educational boards and schools teach English as the primary language, neither English is the teaching medium.
Now, safely assuming the fact that, the majority of English speakers from India do have to learn English as a foreign language to establish communication with the international population, it becomes important to learn English to the extent that s/he can communicate rather than appreciate the intricacies and nuances important for grammatically correct verbal or written text.
Moreover, learning a grammar would seldom hone one's English language skills, but equally important is reading good literary works. I do fear, that most of the English speaking non-native speakers do not appreciate the language to the extent that they would take the pain to read literary works in English.
So to summarize, the problem you highlighted is predominantly among the non-native English speakers who learn the language enough to communicate but not to the extent which enables him/her to write a grammatically correct sentence.