I second the sentiment of taking our learnings from this unfortunate incident and perhaps cleaning up some of the comments. I think we are all in agreement that this was a tragedy.
The vast statistics out there speak louder than the anecdotal evidence or personal beliefs of a few of us on the subject of age. We suffer collectively from overestimating our abilities as well as underestimating just how 'bad' the next person is likely to be at driving just because we are perhaps better or more experienced at a certain age. Speeding on most of our road surfaces is generally a bad idea, especially with reduced visibility and even if you have the skill to handle your car at speed. I'm driving an M5 and over 30... I've done thousands of laps in other cars (RWD and AWD). This car is really fast and requires your wits about you whether you are 18 or 48 years old.
What I am trying to say in probably too many words is that it's not about one thing... speed, age, car's dynamics, power, conditions, experience, parents etc... it's probably about a lot of things that led up to this and sometimes there just isn't a single clear culprit.
There are many stories from many claiming to have personally known him across all forums and groups (and ban-fests are happening in the process elsewhere) eg: he was driving aggressively for his JB4 to learn, had no seatbelt, seatbelt clipped in, racing an A45, daddy got him the car, some holiday pyramid scheme bought the car for him, he earned the money from that pyramid scheme etc. etc. Stories are getting crazier by the day and it is clear that the vast majority of the people who are saying these things don't actually know anything as most are contradictory. Those that really know probably aren't saying anything.
There was a really distasteful thread on the RSC that started off similarly and devolved into 10 pages of people accusing the deceased and his girlfriend of being racing/drunk/showing off and blaming other forum members for the accident because of street racing etc. Probably best to avoid this speculation. We all have guardian angels (or sheer luck if you don't believe in those) that have kept ourselves and others safe during our younger years.