Why do people in this sub downvote valid questions?

I often see valid questions in posts or comments downvoted in this sub, even though this sub is for learning English.

Keep in mind that what seems obvious to native speakers might not seem obvious to learners and non-native speakers.

For example, I don't understand why [this post](https://www.reddit.com/r/EnglishLearning/s/ahFyeLwZz4) was downvoted.

Someone please explain.