I have high standards for things I make, so I'm not particularly interested in using static portraits for the player, especially from other media. The player's appearance is quite variable and even if I attempted to use many different portraits to accommodate every variation combination, they could never match with each other to my standards.
Other characters would be easier, as they would usually only need one or two, but I still would not like using portraits from other sources, as I doubt I could find one matching source that provided all the portraits I needed. So every portrait would likely be using its own style, which is no good for me. And that's not even mentioning having to find royalty-free non-copyrighted images to boot.
The only possible way I can see Paths getting portraits is if it starts making enough money that I can pay a single artist who meets my quality standards to do all the artwork custom for the game. And this is why I decided to add the optional feature for players to add their own portraits. I'll probably be fleshing it out and making it a little more elegantly implemented in the future, but it's currently a low priority.