reality check
I agree 90% seems high, and you're right in the current climate not all of these will get a job to be able to make the repayments!
I can't speak for everyone who takes a large loan - I am 27, have a very good degree, postgrad qualifications and am qualified in a professional capacity, which I can always return to on a salary of c.£70k rising to well over £100k within 2 years (yes - most people think I'm mad leaving it too!). So I know that even if I don't get a job with the airlines, I have a fall back option.
However, I think I am in the minority - at the schools I visted I met many 18, 19 year olds fresh out of school. They are taking a much greater risk by not having a Plan B. Personally I wouldn't have done it this way.
As for the schools - the don't 'encourage' anyone to take the loan. They didn't enquire into my financial circumstances and certainly didn't pressure me to take a loan, but they did offer me a standard business plan to help me get a loan if I required. At the end of the day these schools are businesses and number 1 aim is to make money! So who can blame them for doing their best to get students? However, as for OAT they put all potential APP students through a selection process, so are only offering financial help to students they think will make the grade.
It just seems in this industry, people want it so much, no person or school needs to encourage anyone to take a loan - they will do it anyway!