How does Agent Rarity suck?

So last august I uploaded Agent Rarity and it hit with all the impact of a ball of fluff and I'm trying to figure out why. My proofreaders though it was the best story I had done so far. So what made it so ignored? I know I published it in a dumb way, I set it as finished while forgetting to upload the last chapter for like a month. Which really didn't help since that chapter is probably the funniest and explains why things are happening. But none of the comments seemed to catch that at all.

So in the event anyone is actually paying attention to this blog can you give me some idea what didn't work about it?