SD, I was on the Windows 95 beta "light house deployments" project about 9 months before release.
One of the first things my customer said was "you have to click Start to shutdown?". I raised it as an issue on their behalf, turns out that everyone accepted that indeed it was bizarre but by that time, so many people were using it, that changing the design would have been at least equally bizare. The millstone of legacy and backwards compatibility, until Vista and the new task bar.
My guess is thatthe Mac drag thing is probably for similar reasons.