I guess it is more aimed at those who aren't feeling confident with their way around uni etc, so if you're fine with that, then I can understand not wanting to go.
I went to my first one initially purely because I didn't know anyone else (most of my friends from high school went to other unis or dropped out in year 10), and have made friends and stayed friends with those people from my orientation (and most of us are now the mentors so yeah rofl). It's definitely a good day to just get out and about, see what's on offer, meet new people etc.