User interface consistency means every 'action' should have the same 'effect'. There is nothing wrong with either hovering or clicking to achieve an effect Edit as long as the hover doesn't occupy more screen real-estate End Edit, but the interface should not mix both approaches:
As always, I have an opinion about which approach is right, and I'll explain why. I think SE should choose the 'click' approach as this positively is a user action. Sometimes, the mouse hovers over an element by accident and the user interface changes...
However, hover is very good when the hovering occupies the same screen real estate. For example, a graphical button that highlights when hovered over. That's great feedback to the user.
Edit This is not an exact duplicate as my proposal is the exact opposite from the first question and the second question does not add any proposal. There is a subtle difference between hover, indifferent and click as recommendation.
Final Edit I see the reason for closing this question was changed. I think it could be merged, in a way, with: