I'm a working jazz bassist. Plucking a string is an art unto itself. What struck me about the clip was it sounded like the strings were plucked by something other than a finger.

The point of this research doesn't seem to be to generate a nice sounding digital instrument, but to give violin makers a rough idea of what the instrument will sound like for different shapes / materials. This is useful for comparing designs, even if you don't simulate a human performance with complete fidelity.

So I don't know if your criticism makes much sense.

Every physical model has its strengths and weaknesses. In this case you're correct that no emphasis has been put on the human-instrument coupling, but they've worked harder than usual on the air/instrument coupling which makes sense givwn their goal of helping violin makers. However there are plenty of research work on physical modeling between human and instrument (Serafin, Woodhouse, Chaigne etc from 1-2 decades ago) esp for violin. For string plucking & striking specifically, the coupling is modeled in a few commercial products (Pianoteq is a popular one) [disclaimer: I used to sell a guitar software doing this as well and met some of these acoustics experts a long time ago - these were fun times going down the rabbit hole of physical modeling]

Put differently, it takes years of practice to get a decent sound out of a real violin.

If your model doesn't sound like someone's strangling a cat then it's probably not realistic.