24 September 20149to5Mac:
Many users are reporting that cellular functions and Touch ID are no longer working post update, so we would recommend holding off until further notice. Many who have updated their iPhone 4S, iPhone 5, and iPhone 5s are reporting no problems, so it appears this problem is likely confined to iPhone 6 and 6 Plus.
This obviously shouldn’t have happened. I’m not sure how this got through QA, but I don’t really care. What matters is if a bug of this ilk recurs again, in the future. Then you can say Apple has structural problems as an organisation. Isolated incidents are not signs of poor management — they are (in most cases) genuine mistakes.