Shakespeare wrote:given an appropriate utility function for participants
That gets close to changing the parameters to hide the evidence of failure.
Sure. If you believe that progress in science is "failure" then you're right. Most people think progress is a good thing, but you can call it failure if you want. I am just pointing out two things that I think it's important people know:
1. As in any science, the work of behavioral economists will lead to an improved version of the EMH, not an outright rejection of it. The EMH is wrong the same way Newton's theory of gravity is wrong--it agrees with the better theory most of the time, but in some cases, other theories agree with the data even better.
2. The theory of efficiency in competitive markets derives not from the work of EMH advocates like French/Fama/etc., but from John M. Keynes and Adam Smith. Market efficiency (in general, not just the stock market) is a fairly well established core and fundamental theory of economics.
It seems to me some people hate the idea that the market may be efficient, and every time someone finds a flaw in the EMH (of which there will be many) they throw a party and go on as if the EMH can be ignored forevermore. It's something like the way creationists jump for joy every time someone discovers that the theory of evolution requires some modification.
Science progresses by discovering errors in older theories and producing new, better ones. It's not going to happen that the EMH is "totally wrong" it's going to happen that something else is better. But yes, if it makes you happy, the EMH is wrong. Relativity, quantum mechanics, and fluid dynamics, the theory of evoloution are all wrong too.