I bet it's a misunderstanding of what Computer Science really is. In my opinion, many youngsters or people that's not in the tech world think Computer Science as just programming, or developing a website. I have an experience on this because my parents are forcing me to develop a website in which I don't like and they reacted with "what is your education for?"

But what they don't realized is that Computer Science is more than developing a website or programming. CS deals with math, algorithms, and such words that they haven't heard before. Automata, discrete math, pumping lemma. Computer Science is much harder than they thought. With this, many students in my university shift to another course because they can't handle CS. Too many students are enrolling CS becase they think it is the trend. They think it is the right course to learn how to develop website, how to create something like Facebook, how to develop an app, how to develop something like Instagram, or even how to create a game (http://blog.jpbalb.in/post/16048908922/game-programming-anyo...)! Yes they can learn them through CS, but if that's just what they want, they can just go to the internet and do a Google search. Because again, CS is more than just that.

Finally, I think it's not the lack of staff, but the lot of students. Give those students few years in Computer Science, and I'm pretty sure those "lot" will be "few".