I appreciate the thoroughness of the analysis, even as my eyeballs started to swim amidst the typographical lingo. The article doesn't so much 'explain' the font, though, as explain the constraints under which the font was designed.

Even in understanding the constraints, I can't help but feel that Roboto is a font that's outsmarted itself. All of this hyper-sensitivity to the finer points of smartphone typography is great, but I think it may be achieving effects so subtle as to just not be there for most of the audience. In the meantime, it punts on actually providing a detectable personality (at least IMO). Helvetica has a personality, and eighty years of baggage and connotation that goes with it. A frankenfont is never going to have that.