I wonder why so many prefer reimplementing the wheel (see any sort of Xscript out there) instead of leveraging some pre-existing and proven languages. I don't m

I wonder why so many prefer reimplementing the wheel (see any sort of Xscript out there) instead of leveraging some pre-existing and proven languages. I don't mind if it is something other than C# but I want great IDE support and, most importantly, memory safety + strongly typed.