Well I guess users expect better from one of the largest companies in the world.
Apple is not some crowd-funded startup on Kickstarter or Indiegogo. After announcing the OS months ago, extensively beta testing it for months, and then making a very public announcement of a release date, they should have ensured it was ready for a production release on the announced date ... obviously it wasn't.
Obviously, there was some breakdown in the project management process that allowed the OK to be given to Tim Cook to announce a release date when the product obviously wasn't tested sufficiently enough to uncover a "show stopping" bug.
Working in the industry myself, I understand 11th-hour bugs arise, but the 11th hour should have been before the release date announcement on Sept. 9.