My daughter would have done the same thing. Convinced her to apply to a few “non-ivy type” schools, and she was able to get a full ride at Southern Illinois. So waiting for the acceptance/rejection crunch is not life or death, but an inevitable decision to be made. Pressure about education often doesn’t allow students to understand balance.
If the person applying to 17 even has borderline elite scores and/or writes well, can see them at worst getting into 3 or 4 of the choices (not knowing all of them). But there may have been opportunity passed up by this strategy.