If their goal was to minimize participation and competition, then they certainly succeeded. I don’t think being unfamiliar with something should ever be outright disqualifying.
If I were holding a competition for bakers, I wouldn't feel obligated to include a paragraph explaining what a "bake-off" is. I knew what a CTF was years before I knew enough to compete in one; it's a central part of hacker culture going back to the mid-90s.
Every puzzle here places you in a different unfamiliar situation. The only "outright disqualifying" thing is whether you can figure out something on your own. You essentially failed the first test.
