You can patch meshes in Meshmixer. However, what Phil is talking about and what he has showcased throughout this thead is retopologizing a mesh in another tool called Topogun.
I've looked at it and it is very powerful.
You can do similar things in Blender, particularly when using the plugin RetopoFlow.
What you can do in meshmixer does not re-topologize a mesh. Memento and Instant Meshes also both do not retopologize a mesh. Retopologizing, while requiring some experience and manual work will retain features while drastically reducing the polygon count by several magnitudes. This allows for importing meshes into Fusion 360 and converting them into easily modifiable T-Splines, even if they originate from multimillion triangle count scanned meshes.
Meshes that consist of several thousand quads such as exported stuff from Memento, when converted into a T-Spline are not editable as Fusion 360 just slows down to a crawl.
The other workflow that Phil has described that involvs converting the mesh into SubD and then Nurbs in Maya avoids T-Splines in Fusion altogether.
Whether or not Blender has a steep learnig curve is irrelevent. If a user is looking for a FOSS alternative then there is not much else around. There are outstanding virdeo tutorials available for Blender covering about every aspect ogf it's vast capabilities. CGcookie.com is a great place to start.