It is not our intention to try any bully people into using 64 bit computing. Far from it. Every month now, we include at least one distro designed for older hardware. On the disc in question, this was ArchBang; included in ISO form so it can be used on computers without DVD drives.
At the same time, we don't want people using 64-bit machines to throw away some of their computing power by using software that cannot take full advantage of it.
We're trying to find a balance that will work for everybody. This time we strayed too far into the 64-bit camp. Why? As it happens, Mint wasn't intended to be on the disc, and we'd planned to put another one on in 32 bit form (which one slips my memory). However, as we were putting it together, Mint announced the release, so we changed plans at the last minute. This left us with three major distros to put on each of which, we felt, would be most use on 64-bit machines. In hindsight, this was a mistake.
Going forwards, we will continue to include both 64- and 32-bit, but in the future we'll err more towards 32-bit, and make sure there is always something (usually several things) bootable for 32-biters to try.
For a full range of 32-bit distros, keep an eye out for issue 162 which we're putting together at the moment. This will be a double disc issue, and will include the full Distrowatch top ten (Mint, Ubuntu, Mageia, Fedora, Debian, OpenSUSE, Arch, CentOS, Puppy and PCLinuxOS) plus a few more hand picked ones. They'll be 32-bit so everyone can try them out.
With that all said, I fully take on board the comments about making information about the architecture supported clearer on the DVD cover.