Probably because there hasn't been a major architecture leap in that time. It's very different when going from 32-bit to 64, or going from x86 to ARM. Apple wi

Probably because there hasn't been a major architecture leap in that time. It's very different when going from 32-bit to 64, or going from x86 to ARM. Apple will want to phase that out as quickly as is acceptable to the public, and just like the PPC to x86 transition app developers will probably do it quicker than apple itself. So even if the OS might be updated for a while I think we'll pretty quickly see some apps that just won't run.