Originally Posted by dcstep
Primes are ok, but not needed with today's cameras, so long as the zooms are good.
The attachment to primes traces back to the old film days when shooting at ISO 200 in color was fast, and ISO 400 was about as far as you could go.
Fast primes still have their place for indoor and/or low light shooting. A fast f1.4 prime is two stops faster than the best zoom (f2.8) wide open. The optical qualities will likely be better too. Even with modern camera sensors that can shoot up past ISO 6400 with tolerable noise and VR/IS lenses (which realistically get you one or two more stops of handholding capability), those two extra stops can be the difference between getting a usable shot or not.
From a cost perspective, a f2.8 zoom is over $1500 whereas a f1.4 prime can be had for $500 or less (e.g. Nikon 50mm f1.4). And that prime still has better light gathering capabilities than the fancy zoom.
Finally, the kit lenses that are bundled with the cheaper camera bodies are even worse since they usually have much worse light gathering (f4 or worse). So now we're talking three or four stop difference between the kit zoom and a fast prime.