In my opinion, I think the real issue at hand is not about the brand name behind a camera, but more importantly the aesthetics behind it. For me, the camera is *one* tool in the art making process and just like how a painter chooses his/her brushes to achieve a certain aesthetic, then so should a photographer. Each camera has a different aesthetic and produces a certain looking negative, and you should purchase your equipment accordingly.
I started off with a 35mm camera and moved onto 6x7 because I wanted a longer tonal range and sharpness that would hold up for very large enlargements. I started off with an RB67 (roast beef 6x7), and then finally found my way to my M7ii because I needed something with better optics and portability. I couldn't be a happier camper now because it does everything that *I* need it to do. I buy according to what I need to achieve a certain look to my art.
I don't own a leica, but I can attest to its unique aesthetics. A friend of mine who is an art grad student, bought a leica minilux (point and shoot) and his new work definitely had a new (very pleasing) look to it. He needed something with optics that met his new requirements, and he got it with a leica.
Bottom line is, if you want to know why people buy leicas, or any other camera for that matter, you have to try it out and see for yourself and decide how it fits with whatever you are trying to achieve. Don't buy something just because everyone else has one, buy it because you really need it.
Just my .02 😛