As you said a good content is how deap the author jumped in the topic. Talking about anything from one side and only personal point of view is not enough. We have to give examples from others and maybe use some metaphors to make the text more colorful. About writing skills, it's not that important in my opinion, because that will come with experience and especially we have people from all arround the world, so not all of them can be perfect in the English language. That's really not important because we have here an international community. The most important is to understand each other.
I also like that the proof of brain is a combination of many proofs, work, stake, activity, promotion and others. The most important for me is to see the value in the content, that what will make me always upvote it.
I agree with you. How much a person wants to make himself understood must be more important than his skills. And for sure after a while some time practicing writing it will only improve. I am a person who does not speak English very well, but I have been successful as far as possible in communicating well with the people here.