There were people talking about the housing bubble in 2005. Hell, there were people calling it out in 2003. I remember people calling it a bubble in front of congress in 2006, and being rebutted by the president of some association of Realtors a few minutes later, also in testimony to congress.

The facts of the housing bubble were widely argued during the bubble itself, and yet after the crash, somehow, 'no one saw it coming'.