Most carbs release glucose into the blood stream when eaten and in response, they generate an insulin spike, depending on the amount of net carbs they hold, the glycemic index and the quantity you take.
Starch carbs are more or less dense in this net carbs, yet they act in a more regular, slow fashion that refined sugars and its more natural and most likely the only form of carbohydrates we should be eating alongside with fruit.
So, why would you want to have a blood sugar spike and thus an insulin release? If you are overweight or trying to shred some fat to look like a fitness model, you will try to avoid this because this insulin spike acts as a trigger to start storing excess blood sugar as adipose tissue. This is why VLC people avoids carbs like the plague. No insulin spike, no fat storage so the other hormone, glucagon starts raising in order to release fatty acids from your fat stores to fuel you body because you have to run on something!
But, this very insulin spike that stores fat has also other interesting effects. First, its pretty anabolic, the same way it triggers fat storage it also delivers a lot of nutrients to the muscles and starts protein synthesis, something you want post-workout. It also helps a lot in lowering cortisol levels, the stress hormone, and IMO this may be the best feature.
So if you have an efficient metabolism and are fit, thus don't fear weight gain, you could benefit from these properties. In fact, even if you are not that metabollically gifted or fit, it seems that after exercise, insulin sensitivity increases specially at muscle level via the GLUT4 so that your rate of fat storage lowers and most glucose is used to refill and repair muscle mass.
So that's why most people schedules their carbs after the workout, so that they can benefit this feature for post-recovery, enhanced protein synthesis and less chance to store any excess as body fat.
When you do not train or are generally overall active, you then may benefit more trying to start running on fat, because it fuels perfectly slow intensity activity. But to run on stored fat you cannot have high blood sugar levels because then you cannot release the needed glucagon that lets stored fat start doing its job to fuel you, glucagon and insulin are agonists, one runs when the other does not. So this is why you may prefer to go low carb the rest of the day or in rest days.