My guess is that Jon Skinner was more interested in capturing users to help him make a great editor than in maximizing the capture of money from fewer customers

My guess is that Jon Skinner was more interested in capturing users to help him make a great editor than in maximizing the capture of money from fewer customers. If he wanted to maximize the capture of money, instead of nagware it should be a exploding trial, perhaps for days of use instead of calendar days. Probably the right price for Sublime Text is $49/year with upgrades included or, if not tecnically feasible, $99 permanent with no upgrade discounts. It might seem counterintuititive not to offer upgrade discounts, but Someone who has paid you once the full price is a lot more likely to pay you again the full price for a new version, especially at sub-$100 price point.