Exactly. The mainstream technology isn't at the point in time where 64bit systems are the majority. If a 32 bit system still works, and you could make more money off of it than a 64 based system, its economical. Skyrim isn't meant to be a "New-Gen" game. So get over it. Its made to be a highly polished game of this generation. The next Elder Scrolls game will most likely be 64 bit, have DX12, and the whole nine-yards. But until then, why not just enjoy the end of this generation?
64-bit systems are the majority. If you have a Core 2, Athlon 64/X2, Core i7/i5/i3, Phenom or one of the many later varieties of Pentium and Celeron processors based on the Core 2/i7 then you have a 64-bit system. If you choose to cripple your system with a 32-bit operating system, that is your business but it doesn't mean that you don't have a 64-bit system and it doesn't mean that it should hold the rest of us back. If you have 32-bit Windows Vista or Windows 7, the 64-bit equivalent is free for you. If you have Windows XP, well, it's time to upgrade because it's nearly 10 years old. And if you don't have a 64-bit processor, chances are your system is too old to play Skyrim effectively anyways.
Speaking of 64-bit operating systems :
http://store.steampowered.com/hwsurvey?platform=pc
Right now, they make up just under 50% of Windows installations. By the time Skyrim comes out, they *will* be the majority. If you know how to program, it is not that difficult to write a 64-bit version of the program. The main problems occur when programmers do stupid things like assuming the last bit of a memory address is unused. It's much easier to maintain separate x86-32 and x86-64 versions of a program than it is to say, maintain separate versions for a bunch of different consoles (which have *completely* different architectures). It is much easier to write a program properly and make a 64-bit version from the beginning then to have to go through a bunch of poorly written code later on and fix the bad coding so it works on 64-bit. I assume that Bethesda is designing the Creation Engine to last a while and not just for one game so it makes sense to go ahead and design it so it will last.