This is a pity. I have an app that uses ARC on 64bit, and GC on 32bit. Allowed me to ditch manual memory management without dropping support for 32bit machines.
I've assumed anybody with a almost 10 year old computer doesn't get that much new software. I tend to release supporting the last 2 or 3 OS releases and 64-bit only and haven't received any complaints.
However, you are right, there is little demand for 32bit software; my newer apps require 64bit. But I see no reason to cut off support in an old product.
Had one or two complaints from existing 32 bit users but not much really.
It is nice to have a single complication target now.
I'm not sure if this was a typo or intentional but I like it.