When I think of Rembrandt, I think of his amazingly-detailed, life-like, realistic portraits. There was a market for portrait artists in the 17th century because cameras were still a little down the road. Cameras did eventually affect the art of painting. We get to the late 19th century and suddenly, BAM! expressionism.
I believe sampling, and later, partial streaming of large sample instruments like gigasampler forever altered the role of synthesis. Libraries with scriptable actions like those for Kontakt offered unprecedented realism and expression, and are the tool of choice for orchestral or ensemble mockups. The massive disc, memory and CPU requirements, as well as tight DAW integration pretty much require that these instruments live in a studio computer. Closed, proprietary hardware simply can't compete. What sounds good today doesn't age well, but at least new sample libraries can be easily loaded into a computer.
For gigging musicians, there are many models of stage piano that can handle the sorts of tasks required for the role. You need a variety of pianos, organs, clavs, other types of keyboard instruments, and a selection of the greatest hits of useful synthesizer sounds from the last 30 years. What isn't needed is a accurate, modeled Ehru.
I've been fairly disappointed by acoustic modeling in synthesizers because the programability isn't there. You might end up with a realistic instrument sound, but the extent of editability usually turns out something like, "MAKE IT BIGGER" or "make it smaller." It is like the the more realism we strive for, the less editable it becomes. And why does the model need to live on the instrument anyway? It's just software. A one trick pony works better in the context of a specialized virtual instrument or sonic couture sample library.
When I see a new, expensive digital synthesizer, I ask myself, "how does this justify itself as hardware?" A powerful, editable synthesis architecture coupled to a compelling physical interface is, arguably, a recipe for a $4000 hardware, digital, non-workstation synthesizer. Eschewing physical controls for a small touchscreen isn't.
What I'm getting at is synthesis needs to move on to expressionism. Synthesists aren't clamoring for realism. The camera has won. Synthesis should be used to shape the future, not create cardboard cutouts of the past.
