>Or perhaps we're all part of both groups.

this feels right to me. application development and platform development are both software development tasks, and lots of software devs do both. i like working on platform-level stuff, and i like building applications. but i like there to be a good distinction between the two, and when i'm working on application-level stuff, i don't want to have to think about the platform.

services like fly.io do a good job of hiding all the platform level work and just giving you a place to deploy your application to, so when they start exposing tools like GPUs that are more about building platforms than building applications, it's messy.