I think there's a point buried in Ken's remark, it's just not what he states: a mid-range, low-ratio zoom is great for certain professional use, but can paint you into a corner as an amateur.
As other posters have pointed out, a fast, comparitively-heavy, expensive ($2,000) 24-70mm f2.8 is a great idea for someone who shoots things like weddings. You're doing people pictures, so won't often want to go wider than 24mm, and the classic 35mm film camera portrait lens was something like a 70mm or 100mm. So it's fast, gives shallow depth of field (very useful in a crowded room), and covers most of your bases for making people look good at an event like that.
As an amateur, you're probably going to want something wider than 24mm (say something in the 18-20mm range), and you're probably going to want something longer than 70mm (say 200mm or 300mm). So now you have a middle-of-the-road lens and go out and buy two others? Not to mention, you have no assistant, you're not required to schlep other pro equipment around, so do you really want to carry three lenses?
Then ask yourself: do you spend big $$ on each of these lenses, or not? The cost-factors aren't the same as for full-frame cameras, but I have an 18-300mm for my D-7100, and it basically covers all of the bases except for lower-light, non-flash work. For the lower-light case I can beat f2.8 by more than a stop (f1.8) with a relatively inexpensive prime lens. So for the price of the professional's 24-70mm f2.8, I got 18-300mm, a faster low-light prime (50mm in my case), and an external flash. (Or I got an 18-300mm lens with the camera thrown in for free.)
(Of course the 18-300mm is f3.5-5.6, so it's definitely slower, and I'm not pricing full-frame lenses. Then again, I really do think the D-7100 is the sweet spot for an "enthusiast" amateur camera in Nikon's line.)
EDIT: The OP's question, in the end, is should he get a 24-70mm. The answer is probably "no". The fact that event photographers love it doesn't make it useful for a more generalist amateur. Perhaps I give Rockwell too much credit, but it's my impression that the "professionals use it, so I should aspire to it" attitude is what he's flippantly trying to address.