Why voltage multipliers are not actual "multipliers"?

[001]

Why voltage  multipliers  are not actual "multipliers"?
I cant` get 30V DC from single 16V AC transformer 

[macboy]

A 16 VAC transformer may have a no-load voltage of 18 to 20 VAC (which drops to 16 VAC at full load). At 20 VAC, the peak voltage will be about 28 V, so when rectified, about 27 VDC. So if you set up a x 2 multiplier you might get 40 to 50 V after accounting for diode losses, and depending on the transformer. That is only with no load. Any load will cause the voltage to sag. You need big capacitors in the multiplier to reduce this voltage drop.

[T3sl4co1l]

And significantly worse from a split-bobbin or "impedance protected" type transformer.  Multiplier requires very low impedance from the transformer.

Tim