I proposed most of the original content of the FAQ, including “problems encountered by people learning English”. There is a brief discussion of it on the question about what should be off topicthe question about what should be off topic. I agree that questions that can be answered by a simple dictionary lookup should be closed. I also agree that questions that are posed without background information are good candidates for being closed if the question itself if fairly trivial.
However, as a contributor who enjoys writing answers, I can say without reservation that the most fun answers to write are the ones that unintentionally elucidate something about the language that a native speaker would never have thought of. I would strongly oppose altering the criteria for question acceptance to discourage those kinds of questions, because it will certainly make contributing significantly less enjoyable.
And our main purpose is to encourage questions that the most valued members of the community enjoy answering, right?