The same logic can be used when applying to college (a very similar process). You apply to a bunch of schools, some of which you don't want to go to. If you have your heart set on Stanford and you don't get in, you still need to go to college somewhere.
I guess the advantage of interviewing at companies that at first glance you wouldn't want to work at, means that sometimes you get convinced by talking to the great people there. I've joined at least one company that wasn't initially my first choice for this exact reason.
Maybe it's different elsewhere but every college I applied to I wanted to go to. Between the essays, interviews, application fees, and entry requirements I wouldn't waste my time applying to a place I didn't want to get in to.
I've also cut an interview short once I realized it was a waste of time (H1b formality). If I'm not being taken seriously I won't take them seriously and I certainly won't waste my energy on fizzbuzz questions.
The same logic can be used when applying to college (a very similar process). You apply to a bunch of schools, some of which you don't want to go to. If you have your heart set on Stanford and you don't get in, you still need to go to college somewhere.
I guess the advantage of interviewing at companies that at first glance you wouldn't want to work at, means that sometimes you get convinced by talking to the great people there. I've joined at least one company that wasn't initially my first choice for this exact reason.