The job posting said to send a cover letter and and resume to the principal. It said nothing about filling out an application. Once I got the position, I was asked to fill out the application so they had it on file.
This does happen in small schools.
Also if the job posting does not say to fill out the district job application, applicants may not always know to do that. I know it sounds like a "duh" moment, but it happens. Some applicants send in their cover letter and resume and assume that is their application to the job.
As for sacrificing time for an interview, some applicants literally apply for every job on the job board and do no research into the position until they are called for an interview. Then they finally Google where the job is located and see how far away it is from where they live or what part of the state it is in and decide they do not want to interview.
It boggles the mind how little information some people have about this state and where things are located when applying for jobs.