The English Language Learners site (ELL) was originally made to accommodate English learners that cannot write questions to the standards of the English Language & Usage (ELU) site (which I believe had a humble beginnings of its own). Users were given more slacks so that their questions are not downvoted or removed due to poor quality, simple mistakes, or other minor technical violations. But lately, many questions were downvoted or removed for poor quality, simple mistakes, or other minor technical violations. Perhaps ELL has matured so much that it no longer welcomes the same English learners for whom ELL was originally launched. Maybe it is time to create another website for them. How about a new Elementary English Learning (EEL) site, which will be one step below ELL and two steps below ELU?
I don't see the difference between ELU and ELL as the skill of the folks asking questions, but rather the interests of the experts answering the questions. ELU is for English enthusiasts who are interested in answering questions about topics that you would have to be fairly fluent in English to understand well and their interest is more academic. ELL is for folks interested in helping people learn English as a foreign language, and their interest is more practical usage.
I think we do accommodate beginners OK, although there are instances where I think folks voted to close a little too quickly. That is easily fixed with a post on meta asking for it to be re-opened. A poor quality question, however, should be closed until it is worked into a better quality question. If you're proposing a site where "Is this sentence grammatically correct?" and "Which answer is correct?" questions with no context or explanation are considered OK, I don't think it's a good idea.
It's my perception that learners who put some effort into their questions don't get their questions down-voted, regardless of their level of English. I see a lot of editing and guidance on how to make the questions better, and not a lot of down-voting and closing without explanation, so some specific examples might help change my perception.
I think it would be better to improve what you see as a problem instead of trying to launch a competing site. Yes, there have been many discussions about this in the past two years, but I think it is worthwhile to bring the topic up again if we see things going off course.
DO NOT FEED THE BEARS
What is the difference between the "English Language & Usage" and "English Language Learners"?
How do I determine whether a question fits on English Language & Usage or on English Language Learners?
Wait a few minutes before closing new users' questions?
Less Closevoting, more Editing!
Closing questions from new users
Voting to close questions as off-topic: are we overusing it?
If those questions can be usefully answered anywhere on Stack Exchange at all, this is the site that should be answering them. We don't need another site that covers exactly the same conceptual ground and is simply "ELL, except done right (according to some people)". But that's exactly what your proposal would be.
Instead, make a solid case for what sorts of questions we're currently judging too harshly, explain what we should do instead, and generally encourage the public-spirited among us to do the right thing. I, for one, try my best to salvage poorly-phrased questions whenever possible. But there are a number of questions I simply can't salvage. I wouldn't be able to salvage them any better on some hypothetical "ELL for extreme beginners" site, either. (And since such a site would be far less likely to grow its own non-native speaker experts, I would be rather less interested in even trying.)