I've also seen tech switches used to mask rewrites, because they could sell management on the idea that $NEW_THING would solve our woes when what we really need

I've also seen tech switches used to mask rewrites, because they could sell management on the idea that $NEW_THING would solve our woes when what we really needed was just to spend half a year refactoring the legacy system (regardless of language), but half a year to redo work didn't fly.