There is a flip side to that argument...
A major contributor to our current state of aviation safety is the fact that we fly a lot. The aviation industry has millions upon millions of flight hours worth of data and institutional experience to draw upon. Space flight does not, and it will not so long as the barriers to entry remain as high as they are.
Edit
In response to N_Molson, I could just as easily argue that NASA's rather abysmal safety record is exactly why space exploration should be left in the hands of private industry and eccentric billionaires rather than government bureaucrats.
I think you misunderstood the argument - it is one of incentive structure.
Let's take a different example - science.
It's good scientific behavior to share results and tools, say simulation codes, to acknowledge your own errors whenever you find them, to not let others repeat them.
Now put scientists in a competitive environment for funding. A group now gets a competitive edge by not sharing their code, by not admitting errors and by letting other groups go down the wrong path. The incentive structure has changed - if you want to be successful in this system, you tend to be by discarding good scientific behavior.
I argue it's similar for spacecraft. What's the incentive structure?
I think until enough spaceflight experience has accumulated to pass reasonable regulations for an industry, it ought to be seen as a money sink, not as a money source - you can dump money into it, not get it out.
I'm not saying that this automatically generates the right incentives - clearly safety was not paramount in the early Russian space program either, the incentive was to get a success, no matter what.
I don't mind a billionaire seeing it as a 'plaything' and dumping his money into his idea - that's a similar incentive structure to a nation pooling resources to get someone to the moon. In both cases the idea is to make a goal real even if it turns out to be expensive. But that's not what a corporate incentive structure is - stakeholders typically want to cut costs as much as they can get away with that, not dump money in to make the best idea work. The 'short term cost cutting' incentive structure of corporates has a long track record of lowering safety standards as much as possible (Why get textile workers killed in fires in Bangladesh? Not because people don't know how to build halls with fire exits - but because doing so and installing sprinklers would ultimately make T-shirts 5% more expensive, which means anyone doing it would get out of business because the competition can offer these 5% discount).
So given the very fact that we do not fly a lot into space and lack experience as in aviation, the incentive structure at this point ought to be to dump money into finding the best way to accomplish it safely.
And later, when we have experience, regulations can be passed and then there can be a market like for airlines.