That's just bad service in my opinion...
I personally always do this after curing too though, to prevent deforming the uncured products when removing them. Supports usually end in a thinner point, so breaking them off the actual figure should not be too difficult, cured or not.
You only need to take care when removing them from small, fidly bits, as those might end up weaker than their supports.
I actually find the removing of the supports to be quite enjoyable; the breaking off of the supports makes a nice brisk little sound and I find that breaking them off usually leaves little to no material behind. And the material that does remain, is easily cut or scraped away with a sharp blade.
But the point remains that it's just bad form to leave them on when printing and shipping to a customer. However; it could be that the supports are left on as a sort of transport protection, which would be sort of understandable, come to think about it...