Even now, it's not hard to ask the somewhat specious question of how we can be 70+ years into aerospace tech and we still need our rockets to blow up.
That combination is inherently explosive in any sort of failure.
Historically we can see that there are two modes of rocket development when it comes to failure tolerance. 1. Iterate fast and blow stuff up (e.g. mercury/redstone, spacex) or 2. Iterate slowly, at massive cost, with fewer catastrophic failures (space shuttle, Apollo, SLS).
When it comes to safety, the slow and expensive route has a dubious track record. Of course, slow and expensive is producing much more complex vehicles, until today, at least.
It is obvious that every new rocket that was built from ground up will fail a few times before it is released.
This is not a "production build". And you don't need to explain anything when your "test build" fails, it is obvious some will.