That there are two opposite interpretations of "minimalist" in the article and thread with respect to build-new vs. use-existing decisions probably suggests that it isn't a very meaningful metric.

It would be ideal if you could start with the tactic the article advocates and then easily switch from a stripped down custom approach to a more common denominator standard approach exactly when it begins to have better ROI. But in the real world, switching costs are high, ROI is impossible to measure perfectly, and there are other variables that matter a lot (like your future employees' familiarity with tools). My personal preference is in line with the article's suggestion - I strongly prefer building little purpose built things to reading documentation for and hacking around inconvenient parts of standard tools - but I tend to think it makes better business sense to go with the standard tools for things that aren't directly in your project's core competency.