One is based on boring old analysis, hard numbers, and, worst of all, continually updating the analysis as more information (e.g., Raptor’s severe expectations vs reality shortfall) becomes available. People who use this approach don’t seem to have an opinion of Starship that is trending upward.
The other approach seems to be based on vibes, and trusting that Starship will meet its original design goals despite the fact that no rocket project has ever come close to such an achievement. If there’s ever any introspection about why Starship should be the exceptional project that actually does meet its performance goals, the conclusion tends to be something about how Starship is special because it’s being developed by a private company. And I’ve noticed that, if the conversation does get to this point, you can send it in all sorts of unpredictable and fascinating directions by saying words like “OTRAG” and “Conestoga.”