No patent = legal. Moral and ethical considerations aside but those like politics and religion are generally best avoided on public forums, IMO.
I have no idea why a patent was not pursued or possibly rejected but that is what it is.
One case study to consider re: innovation is the Fein Multimaster. While the general machine was under patent it stayed very much the same and commanded a high price. Since the patent expired we have seen a cornucopia of new similar tools. Over a short period of time Fein has also brought out a ton of new innovations as well as better/stronger/faster machines. The marketplace is packed with innovation from $20 to $600. The patent process worked as it should in this instance. Fein had the time to recoup its R&D, develop market share and prepare for the patents expiration. If you don't patent an idea you don't have the legal protection.
Of all the laws Brandolini's may be the most universally true.
Deep thought for the day:
Your bandsaw weighs more when you leave the spring compressed instead of relieving the tension.