What I absolutely hate is minute picker. 60 items is just too much to scroll. For most usages 5 minutes step is enough and 12 items much better.
As for calendar, I never had any problems with it. Of course it's not standard way that most people get used to, but I think any person will understand what to do.
That's a perfect example of "Apple thought of everything" except how well that feature is hidden from the user. I mean, who was the first person to discover that? And I'll bet money it was by accident.
To get simplicity sometimes you have to remove features, sometimes there's no way around it.
When you face the choice, to hide a feature instead of removing it altogether can be a good compromise. So it can be still discovered casually, it can spread by the word of mouth, blog posts, and of course the user manual.
When selecting text, would you, for example, put select-word/select-line buttons everywhere a text can be selected or just let people discover what triple click does?
The topic is debatable, I just wanted to say that this kind of choice does make sense to me, and probably many others.
100% in agreement with you. I can't remember the last time I needed to add a time with more granularity than 5 minutes. And the iOS date picker actually [does allow for custom granularity](https://developer.apple.com/library/ios/documentation/UIKit/...) up to 30 minutes.
But I guess there is no easy way to accommodate for both those that do need 1-minute intervals and those who would rather have 5-minute intervals (without adding yet another UI element or yet another setting to toggle).
As for calendar, I never had any problems with it. Of course it's not standard way that most people get used to, but I think any person will understand what to do.