I guess the part of all this that spurs us to speculate is that aircraft and all of aviation revolves around aircraft flying, and not crashing, and huge amounts of time, money, effort and training goes into ensuring (or trying to ensure) that they don't crash.
Any way you look at it a 6 month old aircraft operated by what appears to be a well run company crashing in the way this one appears to have is more than just a little unusual.
Looking at what we "appear' to know.
1. Apparently no mayday call (although early reports seemed to suggest there was one).....would be nice to get the straight info on this.
2. An event must have occurred therefore which was sudden and immediately (or nearly immediately) catastrophic, incapacitating the aircraft or crew or both.
3. Most events that we get from time to time in aviation would either have allowed a radio call or allowed the aircraft to continue flying, so it would have to have been that quick that there was no time to communicate, or removed the ability to communicate and incapacitated the aircraft (and/or crew) at the same time.
Not too many scenarios that I can think of that fit with that.