The RPi2 cores are pretty weak as they are well below PPC G3 or Tabor performance. I have a nearly 20 year old free PC which destroys the RPi2 in single core performance. Emulating the 68k CPU is much easier than emulating the Amiga custom chips. Also, JIT cheats and is less accurate emulation.
While you've made your point, a nearly twenty year old CPU certainly doesn't destroy a Raspberry Pi 2 in single core performance. Being generous, by the end of 1997 the fastest x86 you could get was a 300 MHz Pentium II, and the fastest PowerPC was a 266 MHz PowerPC 750.
