Tyritorious on 30 July 2015
Marketability.
Since the roster is very focused on Japanese audiences and tastes, fire emblem is getting a lot of characters. King K Rool is not a marketable character in Japan, therefore he's not a playable character. There exceptions to this, like being the protagonist of a mainline game series, but there's too much against the croc that will get him a roster spot. Maybe in SSB5, still waiting on the name Super Smash Bros Clash (Smash Clash sounds like a great condensed title).
