It was not in any way caused by deregulation. We have to get this right, and we can't let it pass.
F.A. Hayek once noted how important history was to current events: if we misunderstand history, we're going to do the wrong things in the present. So if we think the late nineteenth century was characterized by "monopolies" from which wise government officials rescued us (and, unfortunately, this is indeed what most people believe), we'll have different views on antitrust law than we otherwise would. Likewise, if we think the Great Depression was caused by "laissez faire," that will influence the kind of economic policy we advocate today.
So if people believe "deregulation" caused the financial crisis of 2008, and wise government policy delivered us from it, you can imagine how that, too, might influence future policy.