In my case, my father was intellectually absent and my mother convinced me that programming was too blue-collar. Her father had owned his own heating company and raised his kids to despise anything remotely blue-collar. My grandmother had been his administrative person, and we were raised thinking that being CPAs, lawyers, etc were 'respectable' jobs. Engineering was 'acceptable', if not 'respectable'; ironically we were discouraged from pursuing it because it would "take a lot of math" (wouldn't becoming a CPA require a lot of math also?). And we weren't allowed to take anything apart because "that would void the warranty!" (heaven forbid!). On the upshot, my mother is now an academic adviser and because I've chewed her out so many times about this subject, she advises all of her students to take every math class they can and she has no heartache recommending someone follow a blue-collar path, if that's what the student's interested in.
This is a dire contrast to most Asian parents I've encountered, who seem to think that medical and engineering are the only fields that are respectable. Everything else is a waste of time.
Not the OP, but once upon a time, when you think of a programmer, you'd think of an underpaid, overworked slob hacking away in some dark corner of the office while the cool kids were out having fun.
Quite simply, they thought it would be too hard for me. I don't actually program for a living (yet?), although I do work in a related field where programming knowledge is useful.
So perhaps there was something to it, but I still enjoy programming so I'm going to continue with it as a hobby.