I'm not saying completing such a game is easy but i have to say it's not that hard for 2 dev to finish it either , i know one or two about making games so when i calculate it with myself i see that it shouldn't take that long if they wanted to ( it's not a skyrim game it's just a text based game with bunch of pictures and events ) , as you say maybe is patrons behind all of this i don't know but what i know is it's can be completed much much earlier then 4 years , if they just can't do it they have to put everything they have in hand now in the game and done with it but they rather keep adding content to it and it's make it even harder for them to finish it , i supported TOA game with paying some money ( i don't know if i paid the right person)
Maybe they are too lazy or don't care about the fan who really really love the game like me... just saying...
Sorry if my english is bad thu