Why create ELL when a huge percentage of ELU questions that I have seen appear to be from non native English speakers and are asking for things that few native speakers need. Is there a consensus from ELU mods that two SE sites are needed?
ELU is for etymologists, linguists, and serious English language enthusiasts, while ELL is for people who are learning English. I don't see it as splitting ELU into two sites. Instead, I see it as creating a new site for a different audience. Although the two sites cover much of the same material, they cover different aspects of it, and are thus distinct.
The difference between the sites is the target audience: English Language Learners is for people learning English. As such, I would not expect questions about Old English on ELL, or questions asking a deep analysis about the etymology of a word.
Probably, there are questions that are on EL&U that would have been asked on ELL, if both the sites were created at the same time, but that doesn't mean the sites are two different purposes and audiences.