User blog comment:Rememberthis123/my beef with hetalia/@comment-2241574-20100810022744

To me, the 5 minute episodes distinguishes Hetalia from other anime. Sure, it's not the same as watching something that lasts 25 minutes, but the shortness allows one to watch many episodes without losing too much time (at least in my opinion).

Perhaps there is an issue with budgeting as you say, but I also believe that there are other considerations. One might be that the episodes are based on the original strips from Himaruya, which are short to begin with. Also, it takes time to choose the story and to draw the animation, match the voices, etc.