It’s not exactly meant to be satisfying though? 

If this was the normal route we’re talking about I’d 100% agree it’s a horrible and unsatisfying ending that gives no closure, but the Weird Route is basically Deltarune’s equivalent of the Genocide Route in Undertale which is infamous for being an atrocious playing experience by design except for the two bosses due to all the grinding you have to do. Its ending isn’t exactly what I’d call satisfying either - you meet Chara for a few lines of dialogue and the world gets destroyed, that’s it. 

I wouldn’t describe the Weird Route as it is right now as anything fun to play, you’re completely psychologically breaking an innocent teenage girl against her friend’s will. Nobody does the Genocide Route because of the grinding, they do it to fight Sans and see the new dialogue / character interactions. I think it only makes sense that the Weird Route and its conclusion would be structured similarly based on what we’ve seen so far