I was half joking, obviously this is hopefully not done out of malice and hopefully whoever overloads the operator still handles the case != null logically equa

I was half joking, obviously this is hopefully not done out of malice and hopefully whoever overloads the operator still handles the case != null logically equal to the expected way. There could be smaller differences than true correctness like performance too, not least since the != will be a virtual call that must be resolved, and also the overloaded implementation may or may not be as efficient as “is not null” is. This is a similar same issue as the “what’s wrong with using String instead of string” when it only breaks if someone adds their own type and calls it String, or aliases a type to String (with a capital S). This actually happens in actual code bases for various reasons not necessarily malicious.