I'm not sure what you're trying to say.

You're comparing a terrorist attack (9/11) to reckless malfeasance (this sub). The more apt comparison would be of 9/11 to the Andriana disaster. It's a bit ridiculous to champion the humanitarian benefits of sending a throng of people to look for a handful of people in a very unusual situation while ignoring the larger humanitarian disaster that is far more likely to happen again (ergo far more important to practice for).

And, yes, it's a zero sum game. People looking for the five rich guys are people that cannot look for the hundreds of children trapped on a sinking ship.

At this point, we don't know that there was reckless malfeasance at play. However, there is plenty of circumstantial data to indicate that may have been the case. There was certainly an explicit and willful disregard for expert advice or battle-tested opinions. However, we don't have enough information yet (and may never get it) to conclude that was the cause of the accident.

It could be that someone/something damaged the hull (oceans and boats are notoriously hostile environments) and that created a weak spot that failed under pressure, or that some other mechanical failure occurred. However, those are both every bit as speculative as what I'm cautioning against. They are provided for illustration, only.

Could be? The whistleblower found visual defects in the carbon fiber before they even started using the sub. That's why they fired him. They eventually found more damage and repaired the hull in 2020/21.

You're assuming these searchers would actually be able to get to the sinking ship with children in time. The Mediterranean Sea (near Greece specifically) is quite far from the Titanic site. Exactly how fast do you think ships can travel?