>They are right about null. To say it is a billion dollar mistake is completely over blown. Maybe it was at the time but now a null pointer exception is extremely easy to find and fix.
The whole idea is not to have to "find it and fix it" at runtime... Whether it's "easy" or not it's a moot point, as it is after your program just crashed or got into an undefined state, while your server is running or your desktop user is using it...
Yup, plus depending on the case it might be anything up to insanely hard to find that bug (imagine >100k line code base where will causes a subtile wrong state once in a thousand requests if build with optimizations under load which causes a chain of other subtile errors crashing the production server once a hour).
The whole idea is not to have to "find it and fix it" at runtime... Whether it's "easy" or not it's a moot point, as it is after your program just crashed or got into an undefined state, while your server is running or your desktop user is using it...