We don't need to worry about the carbs if they are healthy carbs. V8 doesn't have any added sugar, the only sugars in it are naturally occurring in the vegetables. So it is veggie juice, with nutrients from the vegetables, and some fiber also. Of course it is better to eat the whole vegetables, but I drink it because it helps me get in an extra serving of veggies during the day. Also, I like it (but not the low-salt, yuck). If you don't like it, there's no problem with dropping it. To replace it, you would just need to eat veggies of your choice to get in your 4 1/2 cups /day.
Life's a journey, not a destination.
It's easier to stay on plan than to get back on plan.