You’ll never catch me opting for a fast f/1.8 prime with stellar subject separation if I can get the same focal length in a zoom lens – even if it means sacrificing a stop of aperture, or even two, at the telephoto end.
But guess what? I don’t care. As someone who, more often than not, finds himself taking pictures of rugged landscapes and adventurous outdoor activities, the last thing I want is a backpack full of different lenses that I need to constantly change to get the shot.