I think it's more nuanced than some people are making out.
I think the billionaire thing is irrelevant, although obviously it allows you to do things that others can't contemplate.
I don't think it should've been so easy for these people to get into this situation. OceanGate shouldn't be able to take money from customers to fund their extremely risky and ill-advised exploits and just sign over all responsibility with a waiver. Telling customers that a vessel is unclassified or experimental doesn't really help unless they know the full implications of what that means - no doubt if they asked, they would've been given the "regulations hinder innovation" spiel. If OG attached a copy of the letter outlying all the safety concerns around their vessel, would the same passengers have paid and boarded?
My issue is not with extreme depth tourism. My issue is not with people having the funds to pay for such things. My issue is that nothing was in place to stop this from happening in the first place. It feels very much like OceanGate's vanity project and their desperate desire to be the first, higher capacity tourist vessel, has led to this. If it was truly about depth exploration, research, and sharing the wonders of the deep, surely you'd want to give your guests the best experience possible and not needlessly risk killing them. If it isn't criminal then it bloody well needs to be.
If very small, round vessels that hold max 3 people, are the only safe(ish) way to descend so deep, then you use those and you charge more. Tough bollocks if most people can't afford it and tough bollocks if it's not a viable tourist venture. Not everything needs to be seen by everyone. Some parts of the planet are off limits for a reason.
The only people getting in those vessels should've been OG staff, fully aware of their own shortcomings. It's infuriating that they allowed others to get in with them, for the sake of lining their pockets.