You are talking about a time when CRTs were a mature technology while LCD monitors were relatively new. As LCD technology and manufacturing process improved, and they were produced in greater and greater numbers, the price fell and LCD killed off CRT even in price-sensitive applications.
Here, E-ink is also a new technology. There is no reason the price of an E-ink reader might not fall from $70 to $7 even as the price of LCD devices falls too. Indeed, your argument could equally well be applied to show that LCDs are inevitably on the way out to be replaced by E-ink displays; people are saying that "LCD is here to stay" and that "E-ink has inferior refresh rate and colour", but that is just the same things they said about CRTs, and E-ink is good enough and cheaper... Even if you accept that only one of the two technologies can exist in the long run, you cannot arbitrarily decide which of the two is the new VHS and which the new Betamax.