Actually it’s not. There is a set_font() function which will increase the font size based on resolution but that is only executed when a dist-upgrade is being performed during boot-up, so that the blue update screen is more readable not when Kodi exits.
It could be called on Kodi exit as well, the only thing is not everyone would necessarily want the font size bigger, and the font size of the console when exiting Kodi would then be inconsistent with the boot time font size, so holding CTRL during boot and exiting Kodi would get you consoles with different font sizes.
A preference option to enable larger console fonts in general for higher resolution modes might be feasible though, taking effect during boot.