I probably have an unpopular opinion, but as a software developer myself I have to be empathetic. In the face of a serious security bug, the goal is to release a fix, NOT to release something fast. If there is ANY time in software development to take your time, it's when a security issue is being addressed. I'm sure there are lots of annoyed people who want group FaceTime, but honestly, would you rather have the security bug?
I also understand there being some time between the reporting of the bug and the response. One week is actually quite fast for an organization as large as Apple. A simple bug report has to go through many layers before it reaches the developers. It first has to be taken and triaged, input into a bug tracker, tested, identified (as to whether it's actually a bug or some kind of user error), prioritized and finally evaluated by developers. On top of that, the PR department in a large company has to tread carefully and determine the most appropriate public response to serious bugs. It thus makes sense that you don't make any statement until you are prepared to. (Look at how often people speaking "off-the-cuff" has gotten them in trouble in recent years...)
I'd honestly say for all of this to happen within one week is pretty quick - I'm sure shutting off Group FaceTime at the server level is not something a small team of developers or bug testers can decide - that decision likely had to go through many layers of management, and the fact that the bug triage, testing, identification AND the decision to shut off a major service was ALL done in one week is, to me, impressive.
I'll say this much as well. Any software developer probably knows the experience of being told by a client or other external entity something along the lines of "Oh come on, you're smart, can't you make it happen faster?" A lot of the complaints about things being too slow or the fact that the bug exists in the first place are simply people who don't understand just how complex software development can be, especially when you are as large as Apple.
Keep calm and wait, people. The world isn't ending. The exploit is closed, and Apple is taking their time to make sure the bug is truly fixed. I'm actually against a lot of Apple's current business practices, but in this specific case I think people need to calm down a little.