Why is a CCV required?

[Turbo_Bimmer]

I know its function is to relieve excess blowby in the crankcase, but why is the CCV arrangement required to maintain a slight vacuum?

My previous E30/M42 and E30/M20 only had a hose going from the valve cover to the throtle body (before the throttle plate), and the excess blowby was sucked into the engine.

Why do modern BMWs require that CCV? Would it be ok to simply run two hoses from the 2 cylinder head covers into a 'Y' and route it to the throttle body or intake tube?
I don't have my X5 yet, but never had that problem on my E46, even in cold canadian weather, but it seems to be more frequent on the X5, so, if the CCV could be deleted it would save a lot of troubles...