To be honest, x86 seems to be heading in the same direction these days. It generally has enough of an emulation of traditional PC architecture for boot purposes

To be honest, x86 seems to be heading in the same direction these days. It generally has enough of an emulation of traditional PC architecture for boot purposes, but look at - for example - how CPU power saving on modern Intel chips requires the co-operation of stuff like the SATA links, or how traditional PC interfaces like PS/2 for keyboard/mouse and HD Audio are being replaced with more embedded-like interfaces such as I2C touchpads and I2S audio links connected to vendor-specific controllers.