Why? Because they were applying Elliot Wave Theory as a rationale for their predetermined bias for the direction they believe the market should take. At least, that is my theory.
One person across the Interwebs that I have seen frequently use EWT in a rationale manner is a man that goes by the moniker Max Cherry. Max is a stats guy, and is always looking for the edge via what has happened in the past. A very rational approach, and he always comes with cool data and charts. Sometimes he applies an Elliot Wave pattern to what he sees going on in the markets. However, he applies Elliot Wave in a rationale manner, by using it to identify where counter trend moves should end within the larger trend. Here's a fine example of his work, posted just yesterday, before this large move up to new all time highs.
Remember, no tool is useful if it is applied and utilized to enforce and rationalize your subjective opinion on what markets "should do".
Thanks Max, for allowing me to post your work.
Edit: someone pointed out; "But, But, he was looking for a C wave lower first!" Well, he primarily was looking for where this move down would end, and the next move up to new highs would begin. That's the point, and it is a far cry from what's typically seen, marking every move down off fresh highs a wave one, and whatever "bounce" occurs a wave 2. Those over the years have inevitably morphed time and time and time again, into a 4,5 when a fresh high is made, and the cycle continues...
The take-away is that Max was looking for a good spot to get long in a bull market, and thus wasn't short and caught with his pants down when the market exploded yesterday.