Comment by Analemma_

Most startups have big upfront capital costs and big customer acquisition costs, but small or zero marginal costs and COGS, and eventually the capital costs can slow down. That's why spending big and burning money to get a big customer base is the standard startup methodology. But OpenAI doesn't have tiny COGS: inference is expensive as fuck. And they can't stop capex spending on training because they'll be immediately lapped by the other frontier labs.

The reason people are so skeptical is that OpenAI is applying the standard startup justification for big spending to a business model where it doesn't seem to apply.