Someone stealing an eBike has the problem of sourcing a compatible charger. This might not be too much of a problem for generic Chinese bikes, but for example the Bosch system requires a very specific setup. If my eBike was stolen, I'd advertise my charger on TradeMe and see if anyone responded, and contact the distributor to asking they'd had any requests for a charger.

My first eBike cost $2200; when I figured out how much I used it I felt OK about spending $4800 on my second one.