I've actually seen this exact situation play out twice (except the new products were not free), though I wasn't directly involved. Both times, it only happened because the business owner was, to put it bluntly, a bad person who had no business (heh) running a company, and the result was a mass exodus that birthed a direct competitor.
To answer your thought experiment:
I am looking at this as an employee, as a controlled person. You are looking at it as a founder, owner, or some other type of position that holds power. A controller.
Those with power would view it as immoral. An action like this threatens their power. Those who have enough power to exert a controlling influence, want, above all else, to maintain that power, while also increasing it. Anything that impedes that is unfair, and thus immoral.
Those without power, or with less power, do not see it as immoral, because it is a redistribution of power to those who deserve it just as much, if not more. It is fair. It is just. It is moral.
You see this as immoral because your sympathies lie with those who have power. Might makes right. The states that enforce non-competes have the same view as you, but California does not, and that is one of the many reasons that it remains the global center of technological innovation.