Midi controllers work plenty good with ipads

Totally agree, and it's an intermediary step, but it's still not the same.

I mean, it's terrific to have an affordable replica, especially for discovery, I'm not debating the price-point advantage (for both acquisition and maintenance), but this is not an on-par replacement.

In an analog (less so in digital, but still somehow) synth, the controls are the instrument itself: they are in a specific place, react in a specific way, and physically part of the device that outputs the sound, and they stay there: you cannot move one without the other. The instrument has its own character. It's still more abstract than a classical instrument like the violin or the piano where the physical action alone is done and felt in real time, of course. It's significantly more incarnated than software + generic (in a good way) controllers.

The good side of this is that after having software replicas or original synthetisers, there's room to build new exciting embodiments/physical instruments.