On other hand it's a mere blog post. You should not be bothered by TCP cost. But reliable data storage and reliability/restore (in case of backups) cost is a concern.
It is mostly a blog post. A usecase for a database that holds tables and rows is very rare in real world. I know noone who uses contacts app in their mobile phones. Access is already there with checkboxes, select inputs and everything for years. Noone uses.
