[fastball]

From watching the launch, my absolutely pulled from my butt guess is that something went wrong with the stage separation system, and that the explosion was deliberately triggered by the SpaceX team / triggered by automated guardrails when the mission didn't go according to parameters.

If that's true, then they can just fix whatever is wrong with the stage separation. And if it's something else, they can probably fix that too. Doesn't seem like it was anything unchangeably / structurally wrong with the entire craft.

[szoszon]

There was a lot of wrong with the launch from the start - failed engines, destroyed pad, parts of the rocket flying off during the start. Yes, it's amazing that it went for as far as it did, but there is no way they can fix all of it quickly.

[fastball]

Everything you just listed is very probably all from a single root cause (the pad not being able to handle the force) and the fix could be as simple as using a bigger water deluge system / having a pad that isn't just a flat block of concrete / etc.

[szoszon]

If they don't have the launchpad designed to not cause all of these issues, why do you think the rest is designed correctly?

[fastball]

Because they knew the launchpad wasn't entirely suitable in advance. And it still got off the pad anyway.

[panick21_]

I not sure if the engines failed or the inlet system had issues with pressure and couldn't feed the engines properly.

[cubefox]

Yes, stage separation failed apparently. Then the flight termination system was triggered.