As with I am sure most here, my initial thoughts are for the families concerned. My second thoughts concern some of the decisions made that night. My third thoughts stem from some of the revelations in this thread concerning what appears to me to be 'pilots' acting totally outside of the remit of an appropriate licence.
With regard to the second, the actual direct end cause of the accident is as yet uncertain. However, there seems little doubt that at least two people should never have been in that situation in the first place. As someone posted earlier, single-engine flying is not inherently unsafe, nor is a single-engine flight at night or over water. But add them all together, and the risk factor increases. Add in icing conditions and the risk factor goes up more. Add in a (potential) lack of pilot experience of the combination of aircraft type and the conditions, and it goes off the scale. We will never know the reasons for some of the decisions that were made, but most of us know the pressure some people can exert and not everyone finds it easy to say no. This especially if you put yourself in the position of someone who possibly should not really have been where they were and didn't have the financial means to stay there. There are very few here who have had years sitting at the pointy end who haven't at some time been pressured in one way or another. There are times it takes a lot to say no, and as other incidents have unfortunately shown, there are times people have failed to say no to the person sitting next to them, and have paid the ultimate price.
Like a lot of others here, I started off longer ago than I care to remember, with a combination of a freshly-minted PPL, youth, big cojones and a limited understanding of just how easily things can go wrong. I was very, very lucky to have had an FI who told me that he'd beat me senseless with a broken rudder if I ever so much as thought about taking any passenger anywhere under any circumstances until I'd got a good few more hours, learned the hard way that things can go t*ts up, and added at the very least some instrument and night instruction. Happily, I went on to do a lot more than that. Equally happily, the way things have gone and are going, I can now stick to gardening and painting the living room. Again.
With regard to the third point, having been out of the loop to a degree, I am as amazed as others to learn about what seems to be blatant abuse of the system. I am unfortunately a little less surprised to see just how little is being done about it. As always, I am afraid, those who play a straight bat are the ones who pay and ironically, who recreive the most attention from the authorities. More and tighter legislation? Of course, but someone has to enforce it. We also have to realise that not everyone plays by the book. You cannot blame the passengers in any way, shape or form here. Almost anyone getting on any aircraft will have near zero idea about the necessary qualifications, and as someone said earlier, to the average person, 70 hours sounds like a lot.
Obviously (to us anyway), something needs to be done. Unfortunately, I fear it may take the sort of event none of us want to see, before someone in a position of authority wakes up to what is happening out there in the real world. I won't hold my breath.