You might think that's a daft thing to say but if you're reading this you probably are doing so from an educated and knowledgeable viewpoint. As someone once said - and I've no idea who it was but they knew what they were talking about - never underestimate the stupidity of the general public.
Is there any evidence that the people boarding these balloons were stupid? I thought not.
There is a particular circumstance in New Zealand. Here there is a universal accident compensation scheme, and NO right to sue for accidental injury. (Let us not debate the rights and wrongs of this arrangement: it's been around for 40 odd years, and successive neo-Liberal/Libertarian governments have not abolished it. They have, though, unwound a whole set of government regulations, in many areas, in favour of industry self-regulation.) An unintended consequence is that NZ is now the home of adventure sports, because there are no accident insurance premiums to pay. This could have an effect on safety standards, but I do not know whether or not it has (there have been a couple of bungy accidents of a startling kind, but they might well have happened under a right-to-sue regime as well.)
Hot air ballooning is NOT sold as an adventure sport: the image is one of tranquillity, and indeed very tranquil they look on a still, sunny morning when we see them from our window. Less tranquil is the one that overflew the city a few years ago, at low level: but the pilot in that case was officially castigated.
What people do for private jollies is up to them, but people who pay for a commercially-offered experience have a right to an appropriate level of safety, and an appropriate disclosure of risk. If you look at a bungy jump, or a jet-boat ride, or white-water rafting, you are not going to think that this is as safe as a drive to the shops (and if you have a clue, you know that is not totally safe, either.) But a balloon flight doesn't look like, nor is it sold as, an extreme sport. So it's reasonable to ask if safety, which can only be guaranteed by regulation, is at an appropriate level. Whether it is or not, I don't know.