So I had a C128D (replacement for C64, which was replacement for VIC20). I had also used a few CP/M machines at this point. I know why they put the Z80 in the 1

So I had a C128D (replacement for C64, which was replacement for VIC20). I had also used a few CP/M machines at this point. I know why they put the Z80 in the 128 but I always felt it was just a stupid thing that the PM/Marketing team should have been told, NO. It would have reduced cost, shipping date, etc. This is a prime example where marketing made the decision without having a real compelling business case for doing so. They could have said 100% C64 compatible with and * that said, sorry no CP/M cartridge support and it would have been just fine.