Without an FOSS free for commercial use version, it can be 1M times faster than Python, no one will care...
It will go the way of all other proprietary languages: 500 people (also counting pjmlp) will use it...
Their FAQ isn't hopeful either, only suggesting that they might eventually open source the standard library.
The best implementation in the article shows an improvement by factor 89. Which is surprisingly low if we assume the processor (Xeon Platinum 8481C) runs with 112 threads in parallel. The final 35k speedup is probably not in question as Mojo will run on GPUs.