I agree that you shouldn't waste time, but I think wireframing is an important and necessary step that shouldn't be avoided or underestimated. When you go righ

I agree that you shouldn't waste time, but I think wireframing is an important and necessary step that shouldn't be avoided or underestimated. When you go right into high fidelity prototyping you are focusing on many elements of the design simultaneously. You are focusing on the coding (html prototypes), visual design, information architecture (layout, navigation, etc) and you are doing it all at once. Because of this you end up giving each department bits and pieces of attention, but not enough to see all the details and insights had you focused entirely on each department one-by-one. I've shot right to hi-fi mockups before and I ended up not seeing a crucial insight in the information architecture side of the project. For me, doing low-fi wireframes and then moving to hi-fi mockups works much better, so I don't overlook certain details and insights.