Its the shortage. It certainly is not that the money is being paid to the older hands. Also, note that the salaries quoted are not starting salaries. So, it looks like more of the "come and join us and everything will be wonderful" kind of nonsense than we know only too well. Of course it is a practical solution to their problems as there are always those who will believe the claims and sign up. So to the extent that they are correct in believing there will be takers they are serving their master well!