As I mentioned in another topic, It is part of our partnership program.
It is not our own Firmware and we don't have our Firmware so we don't own the source code, all users are free to decide if they want to use Vnish Firmware or not.

I asked the same question on that topic. since you brought up the same subject here again,
With your logic, many miner manufacturers and developers are violating CGminer License which also is connecting to your pool. so you are a supporter of them?