That's an option. But it would probably set the world back a decade, maybe two, compared to freeing Mathematica. Even if your Mathematica replacement were read

That's an option. But it would probably set the world back a decade, maybe two, compared to freeing Mathematica. Even if your Mathematica replacement were ready today, it would take years and years and years to gain enough mindshare to begin overtaking Mathematica. The benefit of freeing Mathematica, then, is that it's already dominant. No need to wait out the ever-so-slow shifting of mindshare.