Carbs are not necessary PWO, and neither is spiking insulin through the roof. That said, carbs PWO can be very useful for a lot of reasons. Except for people who are very insulin resistant and prone to fat gain, or people who are quite lean and trying to get leaner, I think PWO carbs are a good idea for most people.
There's the obvious reasons, like glycogen replenishment (if it was in fact glycolytic exercise you did). Then there are other less obvious, but still important benefits. For example, PWO carbs can help maintain a healthy hormonal environment in your body--chronic very low carb can be stressful--without compromising the myriad benefits of a low carb diet, since carbs are best tolerated PWO.
