Not every airline does this. One recent recruitment drive, took on a large number of pilots without type ratings. The ratings were provided free of charge, subject to a sum of less than 10k being repaid in the event the pilot left employment in 18 months. This sum was on a monthly sliding scale. This applied to both non-rated experienced pilots and cadets.
If you read these forums 10+ years ago, you would have seen howls of outrage at any form of "bonding." Together with endless threads along the lines of, "so what can they do about my bond if I jump ship?" Well the answer was simple. They charged you the money up front and if you jumped ship, they simply employed somebody else on the same low-risk /no risk terms.
It never fails to surprise me how few people have researched the evolution of the industry, in order to both better understand the realities of what they face today, and how it is likely to further pan out tommorow.
Even through the current economic gloom, you can still peek behind the hoardings to see the investment that is taking place in certain corners of the training industry, and get a good idea what is likely to be revealed in the near future. One thing is sure, the reasons might change, but the "howls" will be as loud as ever!