Sure, but what happens when your company gets big enough to have backend systems/projects/tools in multiple languages? I've seen this at countless companies, a

Sure, but what happens when your company gets big enough to have backend systems/projects/tools in multiple languages? I've seen this at countless companies, and in my experience it gets ugly fast. You can either shoehorn all schema changes into Django (for example) even for non-Python projects, or you can have different processes for each language, but either way that's a losing proposition vs having a unified, language-agnostic tool. The migration systems built into frameworks like Django and Rails are truly great for rapid development, but they can become a quite a burden later on.