There was a lot of pushback from fans about that, and honestly I think they went too far with differences between the design styles. I especially dislike how drab everything looks with oversaturated blue/yellow color correction.
When you see the Enterprise in the next season, and the new upcoming series, you'll see how it should have been.
They also pulled back on the Klingon designs in season 2 to make them more resemble their classic look, while still being more "modern". Hair, less crazy skin and weird head shapes. Kept the double nostrils.