Gesture driven interfaces and hint animations – good or bad?

Many times I saw statements that "Interface/design you need to explain is a bad design". I do agree with it (e.g. if you have nav bar then having labels under/next to icons is beneficial), but I wonder when we should stop applying this rule. Gesture driven interfaces are quite popular but you need to let user know he can perform some gesture on it to perform action, for example swipe to delete. How user will know he can simply delete item from list without animation that will show this (mobile email clients usually have such animation to show user can archive/delete email by swiping). Does that mean gesture driven interfaces are bad UX? I don't think so, but it's just my opinion.

Are there any studies on topic of using gesture driven interface + explicit hints in form of animations vs simple buttons? Or just on gesture driven interfaces?