1. That was in 1957, not in the 1960's.
Moreover that 4A launch was rushed under extreme schedule pressure and I never read anywhere that that launch was considered a success.
2. It was not intended as a test of an expandable vehicle.
In the week before launch SpaceX replaced 3 of the 4 grid fins on the booster and added new tiles on Starship to replace some that had fallen off while still on the launch pad, because Heavy Booster and Starship were both intended to make soft landings in water. That did not happen, so that is a failure.
3 & 4. They can do it any way they want, but that does not mean that others are not allowed to question what they are doing. Insufficient ground testing does not mean that therefore failure in flight is not a real failure.
5. SpaceX is not doing tests, they are doing trials.
Validation tests are not trials but merely intended to confirm that design calculations and manufacturing techniques are as required. They should be a formality, not a learning experience. Imagine aircraft manufacturers building wings and fuselages that fail again and again in validation tests. That would be the end of those companies.
Objectives of this second Starship launch were that:
- the Heavy Booster would make a controlled soft landing in the Gulf. That did not happen, so that is Failure #1,
- Starship would re-enter the atmosphere successfully. That did not happen, so that is Failure #2,
- Starship would make a controlled soft landing in the Pacific Ocean near Hawaii. That did not happen, Starship exploded and debris landed in the Atlantic near the Turk and Caicos Islands, north east of Cuba, less than 3000 km from Boca Chica, some 31000 km and more than an hour flight short of Hawaii. That is Failure #3.
Failure #1 + Failure #2 + Failure #3 = Total Failure.
The objective was not merely that all engines worked and stage separation worked, although that's the impression that SpaceX and their many fans want to give us. That is not revolutionary in 2023 but was already routine in the 1960's, including hot staging.