It's not that you're a d*, it's just that you lack any kind of nuance

There's a whole spectrum between self-hosting open weight models and having a cloud provider swap models from under you

Should you self host a model if want to maximize predictability to the limit? Yes. Does that mean it's wrong for someone hitting a model on API to expect that it won't switch to a completely different model under the hood from one day to another? Probably not.

Sure, but if you're working in a field where that limitation is not "because you like it" but "because you have to" it doesn't matter. If you cannot assume it to be true, then you have to assume it isn't.