I understand that there are a lot of people out there who dislike the armor in Halo 5, though I think that people are getting confused by art-style and construction.
The Difference: In my terms.
Art-style: Colors, textures, roughness/smoothness, gloss…etc
Construction: The Geometrical shapes that make up the object as a whole, or simply the overall design.
Why are these different? Well the first and most obvious way to point out that the art-style isn’t the problem is that the Noble armor, or at least the Helmet and arms, fit in with the rest of the armor, but look like Bungie’s designs, simply because they are, and in my opinion I think it’s probably the best looking armor, besides Mk 6. This just goes to show that 343 should be able to easily implement all the Reach armor, or at least shoulders and Helmets, without contradicting their versions.
343 does not need to get rid of their designs, they only need to add previous installment’s armor, if they really are trying to make all the fans happy, which I would say easily half don’t like 343’s armor construction.
I would say the main reason the armor looks bad, is because there is hardly any that is simple, armor should be practical, not fancy.