Why 32 bit?

Probably because 32bit is still main stream. It's normal for companies to cater for the bigger section of any market.

Anyway bootcamp does not make you use 32bit. 64 bit will install on an intel mac just fine. You just don't get the drivers.

 

Right -- the big issue is that Apple and their vendors have to supply 64 bit drivers for everything... which aren't readily available, much to the chagrin of anyone who wants to see XP64 or Vista 64 spread....

 

Since Macs use pretty much standard components now, Apple are probably just bundling the vendor's drivers for Windows use. My father for some reason (and against my advice) purchased 64-bit Vista with his new computer and is always complaining he can't find drivers for hardware, so I can fully believe that some of the hardware lurking inside the Mac range only has 32-bit Windows drivers available. Apple aren't going to spend effort getting 64-bit Windows drivers written as the main purpose of Boot Camp is to allow those who have previously used Windows to purchase a Mac yet run their old software.

 

Not much.