Saying 'it's just game mechanics' is a little too black and white in my opinion. Like the previous discussion above, you can sabotage a game and be okay with it because 'it's just game mechanics'. The option to resign is added to this game because it also is in the original games where it was intended by Vlaada that if your game looks so hopeless, there is no fun in continuing to play as well as wasting time. That is something different in a digital version where wasting time is non exisiting. In this case, the game would take 1 more turn (maybe 2 tops). Thats not what resigning is about IMO and not the way Vlaada intended it to be used (thats why the original rules never state that you get 7 points for a cancelled war).
It's also a thing that a player that goes for a cult engine would always go unpunished because War = resign. Ofc the resigning player would be placed 4th but takes the warring player with him.