What a load of crap. A 50 year old today could easily have been a 20 year old AI programmer in 1980, and he probably knows more about technology than the rest of us put together. Computers aren't actually that new, ya know, and are not the exclusive domain of the GenY kids.
I mean, for crying out loud, COBOL first appeared in 1959, LISP in 1958, FORTRAN in 1957, and ALGOL in 1960. There are folks around who have been programming longer than most HN readers have been alive.
There are technically literate and technically illiterate people of all ages, the 50+ thing is pretty much bullshit as any sort of generalization.