More subtly, meaning we express a preference without being able to articulate it, some prefer a very minimalist, uncluttered finder. The M2 is favoured by many for its single frame lines. Those that favour the Nikon series may be preferring not to see the distinct Leica box slap in the middle of the frame with its high contrast. Not saying either group is wrong, like the focus wheel, which unlike the finder you can ignore if you want, some love some hate it.
Photographers have, and continue to, produce great work with both systems. It's good to experience both to see what others work with, this is why, given the opportunity, you should own a Hasselblad 500 series at some point, no prism, and a 4x5, rangefinder finder differences pale in comparison (tortuous pun).