I have to wonder if filming Z was spectacularly expensive in the first season, given that Amazon was willing to write off $7 million in investment in the second season.
If Amazon was going to need to shell out millions and millions more for Z Season 2, perhaps writing off that $7 million was the way to go.
Z has never been a terribly special effects-heavy series, but the period setting may have been costly to reproduce.
Amazon is evidently attempting to reduce spending on original series movie forward; reducing spending by giving up on $7 million seems rather odd unless the costs of production would have been incredibly high.