Your opinion, not universally shared. A search both here and on sites specific to the BMW i3, several mention feeling RWD with regenerative braking was unsafe on slick roads.The FWD RWD debate is important in ICE, not so true in EV.
FWIW, I know from experience, on slick roads too much regenerative braking with FWD can also cause problems, especially on downhill curves. Slick roads are the only time we choose D in the Bolt; less is more when traction is problematic.
So drivers won't have to think is the most likely reason VW chose to limit regen.