Until you can show that books are doomed and have not sold since the 1950s owing to their inability to show TV channels I will assume your reasoning faulty.
Yes, TV has *dominated* -- but that does *not* mean that books have been extinguished, because people still exist who buy them in large numbers. The booksellers don't care that most people hardly buy any -- what matters is that some people buy lots. The same dedicated crew, who include people like me and very probably you as well, will trigger continued production of e-readers: because there is a market. It's not as *big* as the market for tablets, but it's *not the same market*. Both can coexist side by side.