Because “brown” is a result of mixing pretty much any two/three pigments (try it with red and green). That being said, it’s also because plants have usually two or three types of pigments and carotenoids are useful and abundant, and carotenoids range from yellows, to oranges and reds. For mammals that need to camouflage, it was useful to mimic the environments that are murky/shadowy especially since most mammals evolved from animals active in the mornings/evenings – hence ones producing melanin hit the jackpot and blended well with “murky” undefined colours such as varieties of brown.
Latest Answers