That's not completely true. GOAL was their replacement for C. When they were bought by Sony, they were required to switch to C++ so their engine team interoped better with the rest of Sony. GOAL was low-level like C (and also manually GC'd), but macros allowed them to code at a much higher level and reduce boilerplate. This actually makes for a safer low-level coding environment as a lot of little mistakes simply don't happen.
Since they love lisp and Sony didn't specify a scripting language, they decided to write a bunch of libraries on top of racket.
That's not completely true. GOAL was their replacement for C. When they were bought by Sony, they were required to switch to C++ so their engine team interoped better with the rest of Sony. GOAL was low-level like C (and also manually GC'd), but macros allowed them to code at a much higher level and reduce boilerplate. This actually makes for a safer low-level coding environment as a lot of little mistakes simply don't happen.
Since they love lisp and Sony didn't specify a scripting language, they decided to write a bunch of libraries on top of racket.