> Had the Apollo missions failed you would obviously be arguing, using the exact same data, that they 'knew they never had a chance.'

No, an earlier post argued that 6 successes doesn’t mean the odds of success on every mission was high. “Got unbelievably lucky” https://news.ycombinator.com/item?id=43130343

The exact opposite position after 6 failures would be that the odds were good that at least 1 mission would have succeeded.

Obviously, things aren’t actually completely independent, but 6 lunar landings could have successfully been completed with a huge range of different odds. 50% odds of success on the first launch isn’t inconsistent with 6 successful launches or 6 failures, it’s just not enough data to really narrow things down.