you dont have control over it. if you emit a zero stock trade your broker's account (a system outside of your control) it might get zeroed instead of having "no shares bought". this could happen for example if you periodically buy a quantity of shares based on some average of some measurement and zero measurements got taken over the time window. and you can't make that "irrepresentable in the type system" if you didn't know that in advance. did you know that it is a convention that zero stock trades were tombstones?

or imagine your are building something that flies a plane and airspeed is measured as an average of some measurements, and the instrument flakes over your sampling interval. all of a sudden your system thinks you are at a stop. erroring is better because no further instructions based on incorrect data will propagate and shit in the pool.

1/0=0 does not immediately make you stop and think well wait a second, and it could even be hidden behind an function like avg(...)

if you want a nocrash division that's fine but it shouldn't be "/"