My opinion is you can go nuts with any type of eating plan, but yes, I agree that focusing on glycemic index and complex vs. simple carbs makes the focus a little different than saying "no carbs" at all.
On the other hand, restricting my intake of bread, pasta, bagels, etc. has helped me stabilize my weight enormously. And I haven't eaten things like donuts in years. I'm not saying I *never* eat bread, but the longer I go without having it 3-4X a day, the less I crave it. And it's made it a lot easier to just say no to any white flour stuff.
I think all of this becomes a bit more important, once you pass a certain age. For me, it was somewhere between age 35 and 40.