There's a pretty massive difference in the amount of effort needed to publish a post with either of those approaches vs. just typing it into the WYSIWYG editor on WordPress. If your time is worth $60/hour then you're looking at around ~$10/post in additional time spent. You also lose a bunch of features: comments, trackbacks, RSS, etc.
Git commit and push takes a minute or two tops I fail to see how that is less efficient than clicking save in a WYIWYG editor. The setup time between the two options is probably very similar.