If you accepted all the tutorial files, that'll get beefy. On top of that, some might be 16 bit or HDR, which can be exponentially larger.
Aside from what was already mentioned, I've heard that as computers have gotten beefer (like, over the last 10-20 years, not just this year), a lot of coding has gone on to be less and less efficient; if you have a machine with 64K of RAM, you need your code to be like a dolphin's blowhole. If you've got 16GB of RAM, who cares? Code gets sloppier, longer, and the lack of savings gets passed on to the users. Meanwhile, HD space is incredibly cheap (unless you're on a laptop), and there's no reason to care there, either. It's lame, but it's accepted.