Not sure how you got that from my post. As I stated, Mercury lost several rockets in the development process. They used the same iterative engineering process as Space X so it’s nothing new. But, when the goal for a vehicle was to go into orbit and it didn’t meet the intent? That’s not a success. It didn’t work as planned, it was “unscheduled.” I’d also rather have a vehicle that’s recoverable to study the effects of the flight vs losing both stages.
Also, let’s not forget, back when Space X was blowing up Falcon 1s, they were about to lose NASA funding. Elon said himself, if it weren’t for the forth one being a success, Space X wouldn’t have survived. So while iterative engineering is the cheapest way to get into space, having successful launches is far cheaper than blowing up rockets left and right.
I have no doubt that Space X will eventually work the bugs out with Starship. They are on a tight schedule though and it’s still gonna take several successful flights before they put humans in it.