When people say Inference is subsidised, they obviously don't talk about the company itself being profitable. To be fair, I included training costs also.

I don't think that's obvious at all. The price charged for inference is subsidized in the sense that they don't charge a rate that actually makes sense if they want to be a profitable company whose main product is selling inference. If they did want to be profitable, obviously they'd charge much more for inference. Hence, people are saying it's subsidized.