I don't see why writing an operating system and surounding tools in C++ is a crazy decision (I'm assuming you meant windows & desktop apps by saying microsoft). Certainly not in the early 90's, but if you have a big codebase of that already, sticking with it doesn't seem crazy to me.

People make too much of a fuss over the differences between programming language. There are some important differences (whether or not memory safe is a big one, but it is hardly critical to a succful bussiness) but by and large the difference between using say php, python, etc for your program is superficial in the extreme.