I think the apples and oranges have gotten mixed.

Zone 2: the ability to play the same, or a different, source in another locale. "Or a different" is what makes it different from...

Speaker selector switch: which allows the same source material to be fed to multiple sets of speakers. A good selector switch will protect against the possibility of a low impedance being presented to the amp, thus allowing multiple speakers to be driven off the same amp at the same time.

In my rather simple family room HT I combine both. I have a Pioneer receiver with Zone 2 capabilities. I have a four (pair) speaker selector switch connected to the Zone 2 speaker output - with two pairs currently attached. Off Zone 2 I drive a stereo set-up (with sub) in my dining room, and a pair of outdoor speakers. While they are limited to the same source material, it can be the same, or different, from what's playing in the family room. Even off the low-powered Zone 2 receiver outputs, I've never had any problems driving them all to good clean listening levels at the same time.

The lack of Zone 2 means only one source can be played at the same time.

The lack of Zone 2 does not mean that you can't drive the same source material to multiple pairs of speakers using a good (but not necessarily expensive) speaker selector switch.

Or did you guys mean bananas and mangos?