We get a lot of "look" type questions. People are often very interested in how to achieve certain looks with their photography. Calling something the "Leica" look is just giving a name to a particular look that someone recognizes (consciously or subconsciously). I don't think it is necessary to get scientific about whether the "Leica look" is literal, verifiable, and scientifically proven...that's not what's important.
I think what's important is that many people DO seem to recognize "something" in Leica photographs that they call the Leica Look, enough people that there are big articles on the subject online. (Do a search for "Leica Look", "Leica Feel", and "Leica Style"...this is a very common topic in the photography world, with some well-written posts, blogs, and articles on the subject). If there are resources that can be referenced regarding a named photographic look, then that means the question is answerable. The question is clearly "on topic" given that it is about photography. Therefor, instead of debating whether it's a real question, we should simply be answering.
That's what we are here for. To provide answers.