A bubble is not trial and error, its not a discovery process. Its reactions to bad signals, and that is why the trial and error is not called malinvestment (you are getting information), but a lot of the results of the bubbles are indeed malinvestments, and could have been avoided if the price signals would not have been distorted.
Whether pricing signals are "distorted" is really subjective, as pricing might depend on estimates on information that is not known by anyone yet at the time of the investment such as rate of social adoption, political factors, scientific discoveries, and so on. I don't think there is such a thing as undistorted pricing signals as all. The world is a very uncertain place.
you agree without noticing it.
zero or negative interest rates (adjusted) are a signal that almost every investment is wortwhile, a signal everyone gets at the same time.