In fact, beside suspecting that ice crystals at cruise level could have been much more a factor than computers, I'm still clueless about how she finally ended like that.
For a number of reasons, I suspect you are right. For one thing, you would have to assume that AF/AB/BEA knew a lot more about AF447 from the outset than they ever released. They were pretty quick to take action about the pitot tubes. Conspiracy theories aside, they can't afford a repeat and so you would have to think that any initial measures they took would have been directed at what they believed to be the cause. There are also striking similarities between what possibly happened here, and other presumed icing incidents (including the ATSB report that
sensor_validation mentioned).
One problem we are having is how the aircraft shed so much energy (kinetic and potential) and covered so little distance from LKP. This has caused many of us to speculate about a reversal of course at some point. Another explanation may be that the aircraft had a lower total energy at LKP than we have assumed. Kinetic energy must be about right - as I recall its speed was pretty much constant between points. But what about the potential energy.
I wonder what time problems started. Am I correct in understanding that LKP included position but not altitude? If so, could blockage of the pitot drain holes (rather than the tubes per se) cause an overspeed and hence a reduction in thrust? Could the aircraft have been losing altitude for some time before things obviously went wrong? An involuntary descent into a cb cell at night. At some point a drain hole unfroze, then unreliable airspeed......
I guess it is unlikely that multiple drain holes would ice up simultaneously however. Lots of other things seem not to fit with this scenario. If not already there, you would imagine that something like this would get the Captain upfront. Plus you might also at least secure the cabin.
I am sure plenty here will point out other problems with this scenario. Just trying to make order out of insufficient facts.