There would be no issue with that, if you were forced to deliver source code, with comments, and without obfuscation instead of a highly obfuscated binary format.
WebAssembly makes it even more common to run untrusted, random code on your system. The next RowHammer.js will be a lot more powerful.
https://en.wikipedia.org/wiki/LLVM#Front_ends
C++ just happens to be a popular choice because there are many useful C++ libraries, and the compiler already produces very optimized code, so the performance benefit is most noticeable. In particular, I'm excited to get the Lua interpreter, written in C, on the web in a performant way.