The most fundamental goal of Cosmos is being in touch with the real universe.
Having native code, gives you the very best conditions for attaining the desired performance.
- It leaves more headroom, which means you can afford more abstraction.
- It makes it simpler to reason about the actual space and time costs.
Also, many businesses rely on being able to protect their intellectual property. One of the easiest ways to protect that intellectual property, is by not sharing it in near plain sight, as is the case with frameworks such as Java and .Net.
Software written to be interpreted and JIT'ed largely contains all the secrets in a relatively easily accessible form, compared with software written for native hardware.
Native software will take a considerable effort to reverse engineer, often as much effort as it would have taken to just invent the software, which generally defeats the purpose of reverse engineering. C++ for instance, is relatively hard to reverse engineer, because it undergoes static analysis, and usually rather heavy optimizations, that effectively scrambles the intention of the resulting instructions.
Cosmos is directly comparable to C++ in this regard.