As to how well markets functioned wrt the 2008 crisis - one question concerns credit rating agencies. If you believe that they didn't do their jobs well, then it should be troubling that they didn't go out of business, quite the contrary, it's the same small number of firms which still operate in this business. If you believe that they did do their jobs well, because the government bail-out resulted in most junk debt being repaid to creditors, then you essentially don't believe that markets function very well, as they seem to have made a correct calculation that they can extract money out of taxpayers through this junk paper, and that is not what any economist would praise as markets functioning for the benefit of society.
(Two counterarguments to the above that I heard are, the government caused the housing bubble in the first place, or alternatively the government helped smooth/stabilize asset prices, including housing prices, which is a proper use of monetary policy, and the paper was never "really" junk since housing prices rebounded later. Dean Baker argues against the latter based essentially on buying homes getting costlier relatively to renting them in bubble years. The former counterargument is voiced more rarely which is perhaps why I haven't heard a counter-counterargument. Anyway, I think this whole thing is a bit muddy...)