It comes down to making the best of commercially available hardware and OS'es. And the available stuff is PIII or better, so you might as well run XP if you are an MS shop. DOS is more stable, but when it comes to Microsoft, the developer skill sets are weighted towards Windows. I myself haven't written an app for DOS in 10 years.

But you are on to something. Can we invent something that is the opposite of Moore's law? Something like: "Software will become nn% harder to write every two years due to steadily increasing complexity in hardware and operating systems."