Some form of Mathematica has been open for a long time, in the form of Sage etc. There's no reason why academic institutions can't pool more money to develop these further.
Sage is a nice effort, but it isn't Mathematica. I use Mathematica, I don't use Sage. Academic institutions had almost 40 years to "pool more money", yet there is nothing that rivals Mathematica. The reason is simple: open-source doesn't pay well enough.
