Yes, hiring is hard. Yes, as an early-stage startup it will take you a very long time to hire. But you have to remember those you're hiring today will make or break the company tomorrow. Their "5 yr plan" should have no bearing on whether or not they get a job at a very early startup, but by the end of the interview you should know not only that they're technically capable, but can roll with any changes you foresee the company making, and that they have the right personality to mesh with you and the rest of your team (you'll be spending a lot of time together - could you grab beers with them?). You should also know that they're so sold on the idea and vision of your company that their 5 year plan and your 5 year plan become one (or are at least related). Realistically, your startup probably won't even be alive in five years.
Of course I know a lot of people look at things differently, and I have complete respect for different opinions and methods (and love reading about them). We're still trying to figure out hiring ourselves, but I think the best engineers come with all sorts of non-corporate eccentricities. If we had followed the author's suggestions, we wouldn't have hired either of our two founders (including myself) or our first engineer. I'll leave it up to the reader to decide whether that would have been a mistake or not. :)