> Really? Crashes during development are the easiest thing to resolve aren't they?

sure but here we're talking about the edge cases which you won't encounter during development. e.g. imagine you're writing a 3D .obj parser and someone somewhere uses a mesh which for some reason has a NaN instead of a real value somewhere, and your parser parses it and gets a NaN into your system - you'll only encounter the subsequent crashes if your tests had expected such a thing.

now multiply this by infinity - it's impossible to think of everything beforehand. But you really don't want the person to crash their 3D software because of that invalid .obj file, just to show them a pop-up "the mesh could not be loaded" and roll-back to before the loading was attempted.

> Have you met my friend the virtual keyword?

.. what about it ? compilers warn you when you forget it if you aren't using GCC 2.95. https://gcc.godbolt.org/z/d4Yj9z3zf

This hasn't been an issue for more than a decade. clang 3.0 (2011) and gcc 4.1 (2007) already warned for this (and there aren't older compilers on CE that I can test).

There are people who start learning programming today who weren't even born when GCC implemented this FFS