For the longest time, people who built code had liberty to do so without sanction. The idea of intellectual property did not exist. You could work at a company, provide them code, go off into your spare time and do your own thing. That went away for many in the years following the first dot-coms. Now, there are grave restrictions on those who write code. You can even be terminated from a job if you fail to agree to these new terms after the fact. The right way to do intellectual property is to base it on traditional trade secret law and make no provision or restriction to what individuals do in their off duty time.