I liked most of the blog, but it bothers me to see stuff like, "... just as with the introduction of unit testing 20 years ago...".

No, unit testing was NOT introduced 20 years ago. As an example, Perl 1 was released about 35 years ago with a unit test suite that got run on every install. Every version of Perl has done so since, and since CPAN came along, most Perl modules have followed suit. This was the secret sauce behind Perl's reputation for being so portable.

Nor was Perl a pioneer. In fact unit testing was used in the 1960s on the Apollo program, and was even called unit testing. I believe that the concept can be dated back to a 1950s textbook but I can't find the reference.

So unit testing is over 60 years old.