Paraphrasing the first comment of the commit[1]:

A commit message with such a long explanation helps nobody, because it is not searchable by Google, not even by GitHub[2]. [...] If the commit message requires a blog post to be good (searchable) – it is a poor commit message.

[1]: https://github.com/alphagov/govuk-puppet/commit/63b36f93bf75...

[2]: https://github.com/search?q=invalid+byte+sequence+in+US-ASCI...