Interestingly there is also a giant bubble at 1985-86 which wasn't match until around 2010. Looking at http://www.computerhistory.org/timeline/1982/ shows a couple of noteworthy events (Tron and the commodore 64).

Perhaps another reason for low numbers is the difficulty in the major HN has two posts on the front page about it today: https://news.ycombinator.com/item?id=14438601 And https://news.ycombinator.com/item?id=14442410

Perhaps the difficulty combined with the ability to more easily detect cheating/being easier to cheat in the classes are contributing to a slower than desired growth. Given that when plotted out computer science appears to be one growing faster than many others suggests that it isn't that few people major, it's that the science is new and barriers to entry are high? (Annecdotally I know my college had additional barriers to pursuing CS focused on pre-reqs and grades, it's possible a lack of quality CS teachers is causing this as it is so new.)

I never really made the connection of "building websites" to actual computer programming, so CS didn't even come up for me.

but now its 2017 and I went back to school and just graduated with a degree in CS.