It doesn't say _why_ GPU rendering isn't much faster than CPU rendering on Android, it doesn't say why using OpenGL adds 8 MB to the RAM overhead to a process (something I can hardly believe by the way), it glosses over the fact that even though you _could_ render some things at 60 fps using just the CPU, that still means these CPU cycles can't be used for anything else, it doesn't mention the fact that GPU rendering is almost always more power-efficient than CPU rendering, and it doesn't differentiate at all between _what_ can efficiently be rendered by the Android hardware rendering and _how_, besides making the distinction between compositing and 'rendering in a window'.
The final comment about memory bandwidth also makes little sense when talking about CPU rendering vs GPU rendering. Most mobile GPU's use some form of tile-based deferred rendering that allows the use of dedicated on-chip local buffers and efficient caching, to greatly reduce RAM bandwidth pressure. If anything suffers from constrained RAM bandwidth, it's CPU rendering.
From a technical perspective this article is a very naive analysis, at best.