A couple of points I will add to Tony's response. First, you are mashing up the predictions of El Niño and the predictions of winter precipitation into a single thing: they are separate things. In September of 2015, forecasters reported a 95% chance that El Niño would continue through winter. It did continue. The model did not fail. 

Following that prediction and taking it and other important influences into consideration, US forecasters issued the prediction for US winter precipitation: nowhere in the US had a 90% probability of a much wetter than usual winter. The probabilities for a much wetter than usual winter across most of the classic "El Niño affected regions" of the South ranged from 33% to 60% chance. The absolute highest chance of a much wetter than usual winter was 73% in Florida.
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It's true that southern California and the Southwest didn't get the soaking they were hoping for, but the forecasted odds of that happening were not 90%. They were 50-60%. And in Florida, where the forecast predicted the odds were highest, the winter was wetter than normal. (You can check for yourself here: https://gis.ncdc.noaa.gov/maps/ncei/cag).
So, while the actual winter didn;t match the forecast point for point 100%, it did match in some places, which means that you can't make a simplistic blanket statement like "it failed." Reality is more nuanced than that. Tom has written no fewer than three posts (1, 2, 3) devoted to explaining how forecasters evaluate and critique their work. If you truly want to understand Tony's statement that seasonal forecasts may not be perfect, but they are demonstrably better than flipping a coin, you can dive into those articles.
My final response to you is about the nature of your criticism. We can handle criticism of our work, including the opinions of those who question the value of it. We ask readers to offer comments and criticisms honestly but respectfully; to distinguish between their opinions and facts; to refrain from repeating widely debunked myths or conspiracy theories for which there is no credible evidence; and to avoid name-calling, profanity, personal attacks, and general meanness. Your statement about forecasters committing fraud is out of bounds, regardless of the qualifying "seems" and "almost" you added. It's a personal attack on forecasters' integrity, and you offer no credible evidence to support a claim of fraud. We won't publish further comments like that, so if you want to continue to participate here, please keep that in mind.