When Bad Dishes Happen to Good People: Black Bean Soup

I know. It seems like every recipe in TAA kitchen is a winner. After all, when Snickerdoodle Muffins, Key Lime in the Coconut Cupcakes and Butternut Squash Soup come out of it, I may give off the illusion that things never go awry and that every recipe is pure tasting perfection. The reality is that some recipes are...how do you say...duds. I hate to admit it, and I hate to point fingers, but sometimes for any number of reasons, a recipe just doesn't get 'er done. And let's just not even get into mishaps beyond recipe duds. For today, we'll stick with Black Bean Soup. A recipe that seemingly had all the right moves; red onions, bell peppers, spices. But after a 3 hour bath in the slow cooker, it just tasted...bland. There was nothing to it. Even after continuously adding kosher salt (the cure all to just about everything), it didn't change the flavor...at all. Though this was a couple of weeks ago, I remain baffled to this very day. After all, the early ingredients in the recipe looked like this:
And when it looks this pretty, how could it go so wrong?
I refuse to blame this little baby, which has brought many a mean soup and chili over the last year.
After some restrospective investigation, I realized it could be a number of things:
1. I have never cooked with dried beans before. Typically, I'm a from-the-can kind of girl. Perhaps I did not cook the soup long enough?
2. Perhaps it just needed a serious bump up in the spice department
3. The recipe called for pureeing some of the soup and then mixing it back in. Though the wall got a good splattering of black bean juice, that aside, I thought I had done it as instructed. Perhaps I should have pureed more?
I could go on and on. I'm just still baffled by what went wrong, since the recipe seemed to get glowing reviews and I could swear that I followed it line by line. Has this happened to you before? On any dish in your culinary past? Did you uncover the mystery of what went wrong? Give me some love by sharing your tales of woe...