This style of lunge is actually slightly better than the forward lunge when it comes to building muscle, partly because it's harder to compensate with the lower back, so your form is better.
If your goal is to build your quads, this reverse lunging style also beats the forward lunge, which is better for glutes and hamstrings.
Lately there's been much discussion about whether it's more beneficial to do total body training (TBT) or some version of a split system where parts of the body are separated for different workouts.