'Scholar',
Josephus plainly states in at least 6 references that Judah, Jerusalem were desolate for seventy yeras and his presentation of the matter agrees with WT chronology. The fift year text is disputed by scholars and is a problem for advocates of secular chronology as shown by the discussion on the Chronology of Josephus in one of the Dissertations.
I didn't ask you whether real scholars dispute the fifty years. You said the fifty years are specific to the temple. I showed that your statement was untenable, and asked whether you would fall back to the argument that Josephus is unreliable.
All of Josephus' quotes about the seventy years are below. Some do suggest 70 years of actual exile, but do not necessitate it, and overall, Josephus is in agreement that the temple was only desolate for 50, not 70, years. Also, it is illogical to only count the Exile from Nebuchadnezzar's 18th year as exiles were taken prior to that, in his accession year (Daniel) and his 9th year, (and some were only captives from Nebuchadnezzar's 23rd year). So if the Society was right, Josephus would have said that they were in captivity for at least an extra 11 years, even if the time of Daniel's exile was ignored.
Antiquities, Book X, Chapter 7 (partially requoted in Against Apion Book I):
the king of Babylon would renew the war against Jerusalem, and besiege it again, and would destroy the people by famine, and carry away those that remained into captivity, and would take away what they had as spoils, and would carry off those riches that were in the temple; nay, that, besides this, he would burn it, and utterly overthrow the city, and that they should serve him and his posterity seventy years; that then the Persians and the Medes should put an end to their servitude, and overthrow the Babylonians;
No mention of exile, only serving for seventy years, ended by the overthrow of Babylon by the Medo-Persians: 539BC. This seventy years runs from 609 to 539.
Antiquities, Book X, Chapter 9:
the king of Babylon, who brought out the two tribes, placed no other nation in their country, by which means all Judea and Jerusalem, and the temple, continued to be a desert for seventy years;
Desertification does not mean depopulation. (It probably took another 20 years to get the land back properly under control after their return from Babylon anyway.) Obviously the temple was not also a literal desert, so it makes sense that Josephus means that the place was in a poor state. This seventy years fits with the seventy years of Zechariah from 587 to 517.
Antiquities, Book X, Chapter 9:
according as he had foretold to them by Jeremiah the prophet, before the destruction of the city, that after they had served Nebuchadnezzar and his posterity, and after they had undergone that servitude seventy years, he would restore them again to the land of their fathers, and they should build their temple, and enjoy their ancient prosperity.
No mention of when the seventy years started, only that before the city was destroyed, Jeremiah said they would serve Babylon for 70 years. Some time after the 70 years, they would return to their land. This seventy years refers to 609 to 539.
Antiquities, Book XX, Chapter 10:
But after the term of seventy years' captivity under the Babylonians, Cyrus, king of Persia, sent the Jews from Babylon to their own land again, and gave them leave to rebuild their temple;
Some captives, such as Daniel and his companions were indeed captives in Babylon for about 70 years. Josephus says Cyrus sent them back after the end of 70 years, not at the end of 70 years. This period refers to 609 to 539.
Wars of the Jews, Book 5, Chapter 9:
You are also acquainted with the slavery we were under at Babylon, where the people were captives for seventy years;
They were indeed in servitude to Babylon during Babylon's seventy years. This period refers to 609 to 539.
Against Apion, Book 1:
These accounts agree with the true histories in our books; for in them it is written that Nebuchadnezzar, in the eighteenth year of his reign, laid our temple desolate, and so it lay in that state of obscurity for fifty years;
Unless the temple undesolated itself in 557BC, the Society is wrong.