Line length of text

The design spec recommends a line length around 60 characters. (See http://www.google.be/design/spec/style/typography.html#typography-other-typographic-guidelines)

However, this is not followed consistently by Material Design Lite templates and/or website. Some examples:
- The [Text-heavt webpage template](http://www.getmdl.io/templates/text-only/index.html) seems to have around 95-100 characters.
- The [FAQ](http://www.getmdl.io/faq/index.html) has around 100-120.
- The [Stand-alone article template](http://www.getmdl.io/templates/article/index.html) goes up to around 150.
- The [Blog template](http://www.getmdl.io/templates/blog/index.html) seems to follow it.

So the question is: should I follow the recommendation or not? If no, when should I and should I not?