The full-stack superheavy feels like a different situation. Seeing how little control they have over the enormous blast from that rocket is shocking. It feels irresponsible.
One youtube channel [1] showed that a piece of concrete the size of a bus was thrown 50 meters in the air straight upwards during ignition. It almost hit the side of the rocket. This stuff is insane.
Nobody had ever fired a rocket that strong. Their test firings were on par with the strongest previous rockets ever launched, and neither the test firings or those previous launches suggested that something like this was possible.
And it wasn't just them. They went through over a year of environmental review and mitigation efforts. To the best of my knowledge, the issue of how to handle the launch pad being blown over the local environment didn't come up even once.
Engineering is full of things like this. You learn that a problem is possible because it happens. Then you figure out how to mitigate it. That first time really sucks. But when it happens, you have to ask, "Was this something that should have been predicted?" And in this case I'm pretty sure that the answer is no.
They launched the biggest rocket ever made without any of the blast-mitigation techniques used on similar launches.
I'm not aware of a previous case where the concreate launchpad shattered similarly to this. The closest thing to this possibility that I am aware of being discussed in advance was the possibility that the whole rocket could explode on the pad in a large fireball. Which existing blast mitigation techniques would not have helped with much.
In a back of the envelope approximation, an object 10x as big in every dimension has 1000 times the mass and experiences 100 times the air resistance. And therefore flies about 10 times as far. (Only an approximation, there are other factors. For example gravity acts the same on both.)
Nobody anticipated the debris would include large chunks of concrete. And therefore it was able to travel much farther than expected.
They extrapolated from a half-power test, and they extrapolated wrong. Turns out that the exhaust damage is not linear with power. Physical systems are not linear, imagine that.
If the FAA knew that SpaceX could be throwing bus-sized pieces of concrete in the air that could potentially hit the rocket's fuel tanks, I guarantee they would not have approved the launch.
RULE 1: DON'T REPEAT THE MISTAKES OF THE PAST
RULE 2: DON'T FAIL IN UNEXPECTED WAYS
The slow flight termination system was especially terrifying: What should have been an unzip-boom was more like a slowly deflating balloon that took 50 seconds to go boom. If the rocket went out of control at low altitude, someone or something would have been bombed with the largest human created non-nuclear explosion (a fast FTS reduces damage by at least an order of magnitude). At least this will get resolved by the next flight.