Yes, that sort of thing has been discussed on other boards as well (e.g. here).
It makes sense, but with the Empeg you have more options. For example, you can have the user choose to have linear or exponential increase of volume with speed and at what proportion. With the Empeg being a computer, it's more flexible. The in-line attenuator is certainly easier to make, but also less sophisticated. Haven't looked for it, yet, but I will.