Some have to wait until they have worked long enough to climb up the ladder to the point of actually being able to pay their own way.
I agree, I had to work about a year, doing weekends packing fruit and vegetables, 8 hrs per day sat/sun, whilst during the week I was at secondary school. After 1 year at college, I decided I had had enough, and instead of continuing, and going to university, I might aswell spend a small fortune doing my ATPLs, rather then on a degree....at the end of which i would be in debt...no money for flying, not many sponsorships kicking around and stuck in another low paid boring job saving up enough money to do my ATPL's...then at the age of around 30, I would be doing so. But at the moment, I am 17, about to take mod 1 exams, and saving up all the time to get (f)ATPL, but I must admit, my father loves my ambition and is keen to help. But don't think I wouldn't be back in that factory working 6am-6pm during weekdays, and 8 hrs sat/sun, should my father not be backing me up.
And in your thirties you are far more mature and level headed and indeed more grateful at being given a chance to prove yourself. Indeed, loyalty will have been proved to be higher amongst older employees by case study after case study.
And at 30, you'll maybe have wife? kids? mortage? a few loans? money going out each month? a lot of stress at home to deal with? How are you going to justify to an airline that for 18 months you can go without barely seeing your family? and pay off all those bills/loans without work for those 18 months?
In the end tho, I am not the airline. If I was, I would love to see every wannabe through the oppurtunity to become a pilot but there's not enough fortune for us all to share. I just thought, with regards to sponsorship, my idea would be more "friendly" to those with a burning, committed approach to becoming an airline pilot.