Boy, I've really stirred up a hornet's nest with this one, based off of the E-mail's I have received... let's see if I can settle it down slightly.
Some people have commented that the tools are deductible, and that they're essentially "noise" compared to the total price ($5-10mil) of making a video game. True, they are noise, but they're upfront noise. For 99% of game developers, this is money that they have to lay out before they sign their contract. It's one thing for an enterprise developer to drop $2,000 for his toolset per seat to get started. It's quite another for a game developer to drop 5-15x that up front per seat. There's a reason that it's getting harder and harder for smaller studios to get into this industry, and you're seeing it here.
Some have said that the expenses are tax-deductible. True, but that's no reason to go spending everything you can. It's pointless to spend a dollar just so you can save 30 cents on taxes.
Some have said that Microsoft has no obligation to make it easier for developers to afford their development tools, and that is also correct. However, it is in their best interest to keep developers on their platform. Back in the Win32 vs. OS/2 heyday, Microsoft was giving away copies of the Win32 SDK because IBM was trying to make their OS/2 development kit a profit center.
Some have said that Microsoft is using the Express SKU to target the bedroom developer. True, but the interview made it sound like Microsoft was targeting XNA Studio at the bedroom developer, not their Express SKU.
Okay, waiting on the next set of comments...
(Update: To the gentleman who E-mailed me and said, "Just warez it," four words: piss off and die. If it's worth using, it's worth acquiring legally. I'm all for cheap alternatives if they can do the job right, but using warez is a bad way to start your company.)