If every innovator listened to expert advice to stop, we’d have a lot less new things in the world.
They just put people on this thing way too soon.
Take space launch for example. Every significant part of a rocket is tested to destruction multiple times unless it’s already flight proven, then the whole rocket is flown many times before we consider putting people on it. Still dangerous, but this makes it not totally insane.
Trading away safety for cost isn't usually an innovative trade-off by itself, and making that trade-off without any interest in quantifying it is a red flag.
However, for something to be useful you have to prove it. Rush could have contributed if he used his VC money to rigorously establish how many deep sea dives a carbon fiber submersible could make and concomitant with that whether carbon fiber was cheaper than titanium. Rush seemed to object to serious scientific validation but instead did minimal testing. Despite taking paying customers we don't really know anything more about carbon fiber submersibles that we didn't already know before OceanGate came along selling their undersea tours. Maybe scientifically you'd have to replace the carbon fiber hull after 10 deep sea dives to maintain a safe operating environment and maybe that would be more economical than titanium hulls, but seems like OceanGate wasn't even looking for such data. It's not like the hull rating groups were unwilling to work with him on carbon fiber, but he instead refused to work with them.