[hsivonen]

x86 isn't just 32-bit. Linux distros have been reluctant to upgrade their notion of 32-bit x86 to require SSE2. This means that x86 isn't just 32-bit but involves weird 387 floating-point math when other mainstream architectures use IEEE floating-point math.

[floatboth]

Interestingly however, Linux distros have been quick to adopt i686. I remember setting up a router on a small PC with a VIA processor several years ago. Inserted a Debian hard drive into that box — "cmov instruction not supported" instead of booting. The i586 version existed of course, but wasn't the default download IIRC.

[TazeTSchnitzel]

Perhaps they're targeting people with old hardware?

[hsivonen]

Obviously, but everyone with more recent CPUs (as in only 14 years old) who runs x86 packages ends up running less efficient software.