This is neat to discover. On the other hand I dunno how someone would find a practical use for this. Most people would be too scared to try to backdash when it is much easier and safe to just block.
Many times man, there are times were those setups are low/overhead and backdashing avoids the mixup
Also its not about what your opponent might choose, its about building your pressure in a way that you know there are no gaps etc, somebody might just be mashing backdash after he gets hit