The reason behind iOS 7 defaulting to minute increments for calendar appointments is beyond me. Have you ever scheduled a meeting for 8:03? I know I haven't.
In previous versions of iOS, the calendar would increment by 5 minutes, which makes a lot more sense. As it turns out, iOS 7 offers the same functionality, you just need to change a simple -- but hidden -- setting.
As WonderHowTo pointed out, a quick double-tap on the minute column when adding an appointment will change it from 1 to 5 minutes.
Sadly, the change doesn't remain in place; you'll have to change the increment again the next time you add an appointment to your calendar. But in the end, you can save some scrolling time with a quick double-tap.