In Voltaire's "Candide", there is a character who insists that this is the best of all possible worlds. Every hurt you have ever felt, every illness and death anyone has experienced, everything is exactly as it should be. That neither humans nor God could improve upon the world as it is, because any change would make things worse somewhere else.
As the story shows more and more tragedies, natural disasters, wars, and famines, this character needs to come up with increasingly convoluted explanations for how those can possibly exist in the best of all possible worlds. The reader sees just how foolish this idea is.
The efficient market hypothesis to which you are alluding is just the same, stating that the market state is the best of all possible markets.
Why don't you instead suggest why it doesn't exist instead of referring to some random story that is not relevant (he's not making up a convoluted excuse).
> instead of referring to some random story that is not relevant
Absolutely relevant, by analogy. Pangloss (the character from Candide) is presented as a counter-argument to an overly optimistic view of the world. Pangloss's overly optimistic view dismisses all evidence that this is an imperfect world based on a nebulous and unprovable idea that the world is already as good as it can be. hjtkfkfmr's overly optimistic view dismisses all evidence that this is an inefficient market based on a nebulous and unprovable idea that the market is already as efficient as it can be.
> suggest why it doesn't exist
Sure, here's a list of reasons, any one of which is sufficient for hjtkfkfmr's argument to be invalid. Some of these are general statements about the efficient market hypothesis, and some are arguments about it being inappropriately applied to cases outside of an idealized stock market.
* The efficient market hypothesis assumes that all information needed to evaluate a product has already been disseminated. If somebody is unaware of the extent of advertisements that are present in a device, then they may make a decision that doesn't represent their actual preferences.
* The efficient market hypothesis assumes that all information needed to evaluate a product exists at the current time. Since manufacturers and developers can push software updates that change or remove features (e.g. Youtube being removed from Roku, or the "Install Other OS" feature being removed from the PS3), your typical customer who cannot foretell the future cannot accurately evaluate a product.
* The efficient market hypothesis is a statement about the market at equilibrium. This doesn't apply to reality, which is not at an equilibrium state (e.g. technology development, wars, pandemics).
* The efficient market hypothesis assumes that there are sufficiently many actors in a market to test all possible products that could be developed.
* The efficient market hypothesis assumes that an object's worth to an individual can always be assigned a monetary value, and those monetary values can be compared across individuals. That is, if a poor person is willing to spend $10 on a limited resource (e.g. food to survive), while a wealthy person is willing to spend $1000 on that same resource (e.g. food to waste for their amusement), then the "efficient" allocation is to give it to the wealthy person.
* The efficient market hypothesis assumes that there exists a free market. A market in which competitors are bought out and never actually reach the consumers is not a free market.
* The efficient market hypothesis assumes that there are no barriers to entry. If barriers to entry exist, such as the hardware/software design time needed to start a product, the number of people with expertise to perform that design, the number of manufacturers with availability to construct the hardware, etc, then those reduce the number of suppliers of a product, and so an idea may not reach the market.
Can you point me one manufacturer whose is smart tv is simple for the user to replace the software it runs?