Eh, git is good but it is not like he invented source control. Before git there were subversion and before that CVS, along with a lot of others (mostly pay to use).
Git does some things really good and has become more or less the de-facto standard, it does other things not so good (like binary files). But it is not unique.
Some like to keep their calendars clean, which should be their choice. There is already a setting for showing national holidays, they could just expand that