Why do active and passive filters have such fundamentally different responses?
Active analogue filters have an advantage over passive analogue filters in that they use near perfect voltage sources - this means you can mimic inductors with op-amps, capacitors and resistors and build multi-stage high order filters like Chebyshev. 

But, theoretically you can build just as complex a filter in passive components as you can with active components - just look at some antenna filters - they can use ceramic resonators to kill-off unwanted transmitter harmonics and ceramic resonators can also used to reject the transmission frequency in cell-phone handsets allowing full-duplex simultaneous send and receive.

Here's a quick simulation I did: -



It's got a couple of dB of passband ripple and certainly rolls off the frequency nicely above 600kHz but it's a passive implementation.

In conclusion there is no theoretical fundamental difference between active and passive analogue filters.