Why did so few Jewish exiles return to Jerusalem when Cyrus made it possible?
Only 42,360 exiles returned because Jerusalem was a wilderness—barren, with nothing there—and rebuilding required hard work, though it was still home. Many Jews had embraced Babylon's banking system, so precious few accepted Cyrus's decree to go back and rebuild the temple.
Les explains that although Cyrus issued a decree allowing any Jew to return to Jerusalem, the land was a wilderness, barren, with nothing there, and it would take a lot of hard work to rebuild—though it was still home. Of the hundreds of thousands, perhaps a million or more taken captive to Babylon, only 42,360 returned. This was about 535–536 B.C. Nebuchadnezzar had come in 606 B.C., and seventy years later they were permitted to come back and begin rebuilding the temple. Les also notes that the Jews had embraced Babylon's banking system, with its interest and usury, and took it back with them.