grizzled;
Yes, the speculations which are clearly implausible are disappointing. It is preferable that if one does not know, one should stay silent and listen/read/think. The propensity to assume, postulate or just straight pronounce without comprehension is widespread. In a time when one can google and repeat "expertise", deep knowing does not seem to be a requirement for opening one's mouth. But there it is and always will be.
That observed, there are nevertheless a few posts which have focussed on important aspects of this sad, terrible accident. These are, (and this is NOT speculative, but merely a perception of what has been suggested thus far):
1. The notion of "pressure to land" directed towards the flight crew,
2. The kinds of approach aids available, if any, and whether they were used, or whether it was a PAR approach,
3. The exact nature of the weather, esp. vis.,
4. The nature of crew interaction (CRM), SOPs, which will only be available via the recorders,
5. The question of "mission-creep", related to point 1. By this I mean that decision-making path which leads to the 'next step' which leads to the next step etc which were all oriented towards landing rather than an intervention decision which may have broken the accident causal path; This kind of thinking slowly emerges as time pressure (and other pressures) enter the operational decision-making process. They spent a long period holding during which a number of aircraft ahead of the accident aircraft missed and diverted - these may or may not have been discussed and may or may not have factored in any decision to execute the approach.
6. The role of ATC especially in terms of weather information,
7. The role of language difficulties, if any,
8. The last might be the possibility of disorientation/loss of SA (somatogravic illusion, etc - Sochi, Bahrain) in the transition from instruments to visual references the runway especially if the visual environment was like a 'white dome' with little or no horizon.
There are others but it seems that a distillation of posts points to these issues.
All this is, of course, little consolation to the Polish people who have lost heads of state, government people and therefore both history and experience - another point raised in a few posts regarding the obvious question as to why they were all on one airplane.
I take seriously the views of those who clearly speak from experience regarding a historically strict and obedient chain of political, vice military, command which is a very different experience for those in North America.
PJ2