"Faster but wrong" isn't really faster it's just wrong.

> That code doesn't appear to be sequential from other threads is not the language's fault. It's just a fact of reality.

What other threads? In a sequential programming language we certainly can't have "other threads".

> You can still write "sequential programs" like it's K&R.

"You can just not use the bits you don't like" is how we got C++ dialects that C++ proponents love to pretend don't exist. If the language is "simple" except for all the new bits that are complicated it's not simple.