Sure but at those times C and C++ had no immediate replacement, and if you were doing embedded C/C++ was your only option. The same cannot be said for Mojo.
In that regard yes, personally I think Mojo has lost its opportunity, but not due being commercial.
AMD/NVIDIA/Intel now having first class support for Python DSLs or GPU JITs for their APIs, and Julia as well.
There were competitors. Pascal and assembly, most obviously.
It was just a different culture. There was no expectation that everything should be free.