Lack of 64-bit support

I don't know what is happenning to the computing industry but 64-bit is here and is to stay. The first 64-bit capable processor from AMD came in April 2003 as the Opteron, so all machines from the last 5-6 years are 64-bit capable, so, I ask, why are you not supporting it? In processor age, this is 'a lot'. 

64-bit is a good platform that does not just offer more memory access but it also offers faster execution of code than 32-bit. Microsoft provides WOW64 for 32-bit compatibility which is good to keep making 32-bit applications but the implications and the constant switching from 32 to 64-bit makes any process suffer including the actual operating system.

The open-source community does have 64-bit support BUT mostly for Linux. Why not also Windows? In my experience working with 64-bit, it is not very difficult to support the 64-bit operating systems, so what is holding back?

I sure hope that next year we will have more 64-bit applications including the most popular ones which people use the most.