Your anecdote was exactly the refutation of this statement. :) Game developers are often encouraged to work on median-spec systems because games are expected to run on a variety of configurations. You don't want to develop The Sims on a quad-core Xeon with multiple GT680s, only to find that it doesn't run on your mom's 2005 Core 2 Duo with integrated graphics. The people working with the asset pipeline/level editor might want some extra horsepower (end-users aren't expected to be able to run the level-editor, so it's usually not very optimized) but the programmers don't frequently need it.
Also, though, I disagree with this:
> a startup doesn't have to think of liquidating their assets unless they are going out of business
The most important thing to keep in mind, as any sort of business owner, is your BATNA (http://en.wikipedia.org/wiki/Best_alternative_to_a_negotiate...). It drives all your major decisions--should we raise funding, should we get acquired, should we IPO, should we declare bankruptcy, etc. And the "baseline" BATNA is always "how much money would we have as runway if we just liquidated everything, fired everyone, and started over?" It shouldn't be a consideration, but it should always be a benchmark to observe your distance from. More liquid assets means more negotiating room, basically.
But really, my point wasn't about liquidating assets, it was mostly about cashflow. A startup, like any business, both earns and spends money. Leasing means you have more cashflow. It's the same reason you don't buy physical servers right away--you don't want to lock that money up if you don't know if you'll need it.
You're falling into the consumer trap of thinking of the value of an item as its initial, un-depreciated cost. Apple products are almost liquid assets--you can sell them for large fractions of their original purchase price for years after you buy them. Whereas most PCs, like cars, plummet in value the moment you take them off the "lot." Which do you think a startup would rather put on its balance sheet?
Also, because Apple products don't tend to depreciate very quickly in the market, Apple is willing to re-attain their own products after lending them to you for a while: they maintain a very competitive leasing program for businesses (http://www.apple.com/financing/business.html), which you can get into as soon as you want to lease $5000 worth of hardware (i.e. as soon as you're at least a two-person shop.) This is basically the Heroku/AWS of computer hardware: you need fifty laptops for a year? Pay as you go. Want to upgrade? Return them and get new ones, no charge. Business fail? Send everything back, you're good. Business succeed? You can buy the stuff out.
I would bet [fairly large amounts of money] that the majority of startup in SV/SF who keep Apple hardware are on that leasing plan. As soon as you mention anything about "starting a business" around an Apple Store employee, they throw someone in a black shirt at you to explain it.