You need to consider that the President of Poland was known in the past to make the determination if a plane should procede or not and that against the pilots decision. Plus the fact it took four passes speaks volumes to the weather conditions. Clearly this was an accident and the black boes will reveal that further. It is very likely the piolet determined the flight path with a possibility the Pres. might have said to land and not go to the other airport. It is well documented that the ultimate decision is the pilots not the towers.
Am wondering, as well; why even four passes attempted; and they were told in some fashion to 'abort' or move elsewhere. So in this damning fog; they were to just move on? Or to try again; not once/twice but 'four times'? (Were the lights on for this pilot? Did they speak more Russian than English? And not a word of Polish?) Whatever the case, am betting that the Pilot knew Russian. . .AND English. But that will be for later.
Meantime, the pilot certainly must have thought he had a reasonable chance of landing; so just how bad was this fog; that pilot chose to ignore warnings - if in fact he did 'ignore' - and not just try to follow some confusing and contradictory commands? (Other planes turned to alternate airport; per report. . .were they from Poland? What language did these pilots speak/understand?
Hope Polish Authorities have at least, equal control of black box info; but suspect this is left - as we have read - to Putin's final authority per his stated intention of controlling investigation i.e. the Russians have first crack at it - or perhaps, more fairly per 'black box' at least - they will not.
As time goes by; more confusing info will be cast here; though that does not change, necessarily, the final truth of the matter. A truth we will probably never have confirmed, at least, confirmed without leaving a doubt.
It seems a 'second hand' of Stalin, reached out here and am not sure how a tragedy so profound, unfolds; without so much as a push by evil intention.
That said, of course, not only do 'accidents happen'; but life happens; and too often in ways, that we cannot fathom.