The optimism and buy-in that excited people about tech from the debut of the iPhone until fairly recently was a function of PR and technology marketers-- like the author-- doing their jobs very well. For any industry, generating interest and excitement is more than a purely descriptive process. The magical venture doesn't just appear and then the marketers have the simple job of describing it. Marketers/strategists/PR people play a very important role surveying the project and then articulating a compelling vision. That vision then becomes sort of a self-fulfilling prophesy since stakeholders (both creators and users) have bought into the promise of worth.
If strategists aren't able to see a path forward, to survey the field and identify the things that make the project worthwhile, exciting, sustainable, tactical, etc... then they're just not great at their job.
Admitting that you haven't really believed in anything you've worked on as a marketer is a bit like an actor admitting that someone else is reading their lines. A good marketer, like a good actor, lives in their promises like they are already real. The realer and more convinced you are, the more you can speak your vision into reality.