There's nothing inherently wrong with e-books - and they are an absolute boon for those studying literature - but if they were to become the only way of reading books, we would be in a terrible place, civilisationally speaking.
There is SOME evidence that e-books are driving out PAPERBACKS but not hardbacks. In other words, we might be seeing a re-adjustment of the market rather than the extinction of a whole medium. In any case, it's very rare that a new medium fills an old one; there is usually some reconfiguration of the old to meet new circumstances. (Radio didn't kill newspapers, but probably caused them to change. TV didn't kill radio, but caused it to change.)
I'd be quite surprised if Bradbury's books appeared a e-books, just because I know he is personally hostile to such things. But if an author wants to make money from his work (rather than be ripped off by unscrupulous pirates), he probably should put his work out there in all the forms the market supports.
[Norman Spinrad wanted to put all of his books out as e-books, but didn't have digital versions of many of his pre-computer manuscripts... so he went online, downloaded pirated copies of his books, tidied them up to match his approved manuscripts... and then offered them up as authorised, pay-the-writer e-books. He called it "pirating the pirates". Better HE should make some money, rather than the pirates.]