They sure can. But, if they were truly good they wouldn't need to grow on people since the people would like them from the beginning.
I don't agree that if you don't instantly like something the minute you lay eyes on it that means it's bad. I'm not crazy about all the icon choices but I can say the same thing with iOS 6. At the end of the day I think all this obsession over the icons is stupid. Most people don't spend much time looking at app icons. And if we're to believe a lot of people on this site, the stock Apple apps go in a folder never to be seen/used again because they're using all Google apps or whatever.
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Because I think "growing on me" means that you are going through a process of learning to accept them. If you liked them or if they were "ok", you wouldn't need a while to settle for it. It seems like people are making the best out of a disappointing situation. (Note, it's just my personal impression.)
I think people's personal feelings are being projected on others. I don't like the icons, or I don't like ios 7 therefore its not possible that anyone else could, and if they do it's because they're just settling for it. Again, I'm not crazy about all the icons but I think WAY too much time is being spent focusing on them. There's plenty of icons I dislike in iOS 6 but I don't really care because the amount of time I spend looking at them is next to none. I'm actually in apps doing things, not staring at my home screen.