You picked one example (Apple) that supports your thesis (technology is cyclical).
It is, however, an exception to the rule.
Computer industry is littered with bodies of slain giants: Borland, Sybase, Lotus, Wordstar, Personal Software (VisiCalc) etc. The rest are companies that stabilized into a success (Oracle, eBay, Microsoft).
It's exceedingly rare to make a come back (IBM, Apple are 2 examples I can think of).