Same here regarding skill level. I am neither fan ('cause I doubt I can do it) nor foe of it ('cause it looks OK). I am just genuinely curious why
@Sleboda disliked it enough to make it
numero 2.
Spawning of Bob nailed it, but I'll elaborate a bit.
First off, I am a supporter of the arts, of creativity, and of individual expression. I'm something of an artist myself, as it happens.
Second, I will
never diminish the talent required to paint NMM.
Lastly, I know this is just an opinion and that not everyone shares it (though, as you'll see, it's not all that far away from fact as an idea - it's just my idea of whether it should or should not be used that is an opinion).
That all said, NMM as it is used when applied to three-dimensional surfaces, is one of the very few things in art that I would say with conviction is actually
wrong.
This is not pink orcs, or an army of Khorne warriors returning to fight for the Empire under Sigmar's banner and thus being painted in the colors of Altdorf. We're not talking fluff or color choice. We're talking about what Bob said - NMM looks great in static, flat images because
that's where it is appropriately used. The moment you move the model OR your head when looking at a 3D model, the technique fails. It becomes the wrong approach for the task.
Just to make up, right on the spot (and thus not all that well thought-through), a comparison, I would liken it to a family that is looking for a home choosing to move into a Hollywood movie set version of a home. On the screen, when shot how the director wants it, a home in a movie can look amazing. As a home in which to live, it's not the right choice. Chances are the plumbing does not exist, the walls are not load-bearing, and the whole place would fall over in a storm. If a family bought a home based on how it looked in a movie, they would have made a very poor choice and would realize it almost as soon as they arrived with the moving van, if not sooner.
NMM is like that. It's all flash and no substance. It's an egregiously obvious example of form over function, of style over appropriateness.
Where it CAN be great on models is in a shield design or banner design. These things, were they "real" would be like a magazine photo or museum canvas painting. They would be 'moments in time' on a flat surface.
Using NMM on a sword, piece of armor, or whatever results in the error Bob illustrates.
NMM is actually
wrong for the task at hand.