With regards to the bigger picture of 6 pt vs 12 pt, it all comes down to situation and what trade offs you're willing to make. The open ends were by far the worst, which is to be expected, but people still buy open end wrenches and use them because they are required in certain situations.
That same logic is why my box end wrenches have 12 points, and why almost every socket I own is 6 points. If I can fit a socket then I'll use it because using a ratchet is a lot more convenient, and your engagement angle is only limited by the number of teeth in the ratchet, rather than the 6 points of the socket.
The only way I'm using a box wrench instead of a socket is if I don't have enough clearance to fit the socket and ratchet. And if I'm in a spot where there's not enough clearance for a socket, it also means I probably don't have the clearance or swing to use a 6 point box end wrench. If I'm in a tight spot I'll trade off the extra grip of 6 pt for having more positions to put the wrench onto the fastener.
Lastly, you have to take into context the torque values each of those failed at. Even the 12 pt box ends failed at well over 100 ft-lbs on extremely rounded fasteners in 9/16" size (about 14mm). By most standards used in the auto industry, a 14mm bolt head would be used on either an 8mm or 10mm bolt, where recommended max torque of a Class 10.9 bolt would only be 60 ft-lbs. Of course with corrosion or damaged threads the removal torque could go much higher, but he needed to use a cheater bar on every wrench to get it to slip. The 6 pt might have held on longer (in fact until the barrel nut actually failed itself), but the chances of you needing to use a standard length wrench 12 pt box end on an 8mm bolt to crank 130+ ft-lbs is very low - at that point you're not even really using the right tool for the job, or you're dealing with some other type of issue.