A PC-Card slot can do everything a CF card slot can do (since you can put CF cards into them, with a very simple caddy). A PC-Card slot can do everything an Express Card slot can do (again, just need a caddy). But specialized CF card devices aren't anywhere near as common as PC-Card devices. Just go look at the cell carriers, and show me how many supported CF card mobile modems they have. Now go do the same for PC-Card and Express Card devices.

That's why it shouldn't have a CF card slot. It should have a PC-Card slot.