This is addressed through various release notes and in the forums here multiple times.
12.04.5 better supports 32bit hardware kernel, drivers, modules, etc.
The older kernel is responsible for this wider range of support. Why?
Because with each release of a new kernel, drivers, modules, etc for older hardware is dropped that was once supported in previous versions of the kernel.
Never is a dangerous word to use, but probably not, anything old now is 64bit and as stated earlier the other one better supports that platform anyway.
So when 12.04 reaches the end of it's support life, those of us still needing a 32-bit system will be forced to find another distro? Or just keep using 12.04 without support until our hardware finally quits. I've got an ancient relic here that Linux has kept out of the landfill for years! It'd be a shame to toss it because even Linux is too much for it...