Huh? Why months to pack up?
He said build up a cushion. As in saving money. Shocking as this might be, a lot of people live paycheck to paycheck. My last boss made $100,000, his wife more than that, in Iowa, and they still had money woes. Which strikes me as crazy, but hey, not everyone has the best financial restraint.
Seriously what could possible lock you into a single location?
Family. A lot of people get such a large benefit from their local family support group that they would be devastated if that simply went away. Ever look at how much quality daycare costs in Boulder Colorado?
Alternatively, the spouse. Changing cities is a major life change and it's best if everyone is on board. And they can have careers that anchor them to a city just as much as you want to leave it. Whose career is more important?
And lastly, friends. You know how most people get their jobs through "networking" rather than their resume or merit? Guess how many friends people typically have out of town.
Oh, but hey, you don't have any commitments or responsibilities as a 20-something tech professional and you think hopping on a greyhound to Silicon Valley is a viable choice for everyone else.
Personally I think that even if you're cash-strapped with family bonds, you can still shop around on the international/global market for a better job. The worst that happens is you decline the job for not paying enough. If you find something that warrants the move, and I mean it pays off the moving costs and counter-balances the lost roots and all that jazz, go for it.