Presentable wireframes sell the project in a good way in some cases.
Great article. I know I'm guilty of spending too much time aligning stuff and making high fidelity wireframes.
I think it really all depends on the client. Some clients enjoy seeing the wireframe before the high fidelity mockup. So if that's the case, then you do want things to be presentable. If not and it's only for reference, I think a quick wireframe is fine.
What about the idea that wireframes are a great way to get the client to sign off on the functionality of whatever you are building? Certainly can't show scribbles and whiteboard images to a client. Sure it might work well for small team/lean development. But not for more formal practice.
Maybe trying to make them pixel perfect is the real issue, which really isn't the intention of wireframes. But they are essentially web blueprints, and should outline everything functional prior to the graphic execution.
Blurring too many steps of the design will definitely slow you down.
I have recently been using Invision App to tie together my PSDs and I think it helps clients see how things work and flow. Most clients I work with have a tough time looking at wireframes.