You guys are tall ship masters. Your vessels are generally well understood these days but let's not forget some comparable disasters: Vasa and Mary Rose. Yes both are from a long time ago but both were based on top of a lot of good solid engineering but both pushed the envelope somewhat and perished. Vasa design basically forgot to sort out the various CoGs for a ship - it was top heavy. Mary Rose loss is a bit more complicated but for me water ingress via lower open gun ports, compounded by heavier loading was a possible failure scenario.
I'll also recall the sinking of the Herald Of Free Enterprise - a roll on/roll off ferry that departed Zeebrugge and "rolled over" in shallow water due to the bow door being left open - ie stupidity and a lack of monitoring. That wasn't a tall ship but the same general rules apply.
Those are three samples from 400 years of maritime history. The Vasa was a daft design from the outset (meta vs cog), Mary Rose a daft refit after 30 years of service (it was OK for 30 years and then wasn't) and Herald was basically abused by her crew and lacked monitoring.
Now submarines are pretty new. We do have a fairly long history of making pressure hulls from steel and some other materials but they all build upon earlier designs and they have all been tested with a lot of loss of life for failed designs - the history of submarines is pretty sad.
I gather that all very deep sea hulls are basically spherical. The Titan's pressure hull was made of carbon fibre which I gather no one else has used like that. As well as a novel material its shape was elongated to allow more passengers - that's two changes. Finally we also have a viewing port at the front that was actually tested but never rated for 4000m.
No one really knows what happens to carbon fibre pressure hulls when they go from one atmosphere to 180 and back again, repeatedly, then they are picked up out of the water - more stress and strain. Also, no one really knows what happens at the interface of a "window" to carbon fibre at 180 atmospheres.
There are lots more questions to be answered but frankly I see a company trying to run a submarine with DevOps attitude (move fast and break things) rather than proper maritime grade engineering. At 180 times atmospheric pressure, you die within seconds. No ifs and no buts.
I absolutely stand with you guys in insisting on standards for this sort of thing. It isn't the same as running up Everest or going into space. Deep sea is way, way more dangerous.