The people running these courses have potentially conflicting aims: they want your money, but they also have aims to do with the course - the balance of the class (students with a mixture of backgrounds/interests/aims), the size of the class, whether an applicant will be able to keep up - if not the rest of the class will be held back, the assessments will involve more work for the teachers, and so on. The tutors are human; they want to run a happy/successful/productive course.
On my CELTA course, we asked the tutors if they had ever turned anyone down; they said they had.
Keep your fingers crossed! [This is a British (and American, I think) expression, meaning 'hope for good luck'.]
;-)