I didn't know Apple was in trouble, but iOS 7 is an okay operating system. It's not the greatest. I think Apple could have done more with it. It is nice you can open up more than 7 web pages and organize all your apps under one section. The color scheme is alright but if Apple is in trouble I doubt it will save it in the long run.
The iOS 7 has some interesting differences, but like the past operating systems nothing significant has changed. If they are struggling now then they would need to make a more attractive and appealing system that no one else has or would of thought to get. It is unlikely that iOS 7 alone will be that difference.