Once again Pilot Pete has hit the nail on the head.
I think what many lose sight of is the fact that somewhere along the line someone had to pay for said 'ATP Cadet'
Very few airlines now dont bond you or ask you to make a contribution or even pay for your own type rating. Even DHL who 'pay' for your rating have you on reduced salary for two years. That is 26k for 2 years and then up to 40k, and you are bonded for your type rating during this period.
With the ATP scheme as PP Points out you go straight onto full salary after your 6 months is up. Often this puts you out 14k in wages you would have got, if you could find a jet operator who would take on a low hour guy and pay him from the outset as well as pay his/her type rating. Happens I know, but rare as rocking horse $hit. So the AQC cost net 4k(They give you 2k back), all in all it has 'cost' you around 18k which is about what a type rating is with the only cash changing hands at the AQC Stage.
The allowance is around 1k a month and is net (i.e. after tax) so is about the equivilant of getting 16k a year. Not that bad in the grand scheme of things. Emerald pay new entrants less than that, after taking money for your Type Rating and I dont hear many bitching about that!
Going straight onto a jet is quite rare and the more likely path is onto a Turbo Prop or instructing. So the money is a bit tight for the first six months for everyone starting out, but this helps you climb into a jet 3-4 years earlier than you would do had you followed the more traditional routes. All for an initial risk and outlay.
Lets not forget people are still paying upwards of 50k to get just a type rating and 200 hours on type, and 20k for a type rating with no hope of a job. I would say the experience far outweighs any financial reward, which incidentally you will get after you have proven yourself worthy.
At the end of the day, if you cant live with not being paid much for the first 6 months then dont apply, but I would say now is the ideal time to apply as another major UK Operator is about to take 10 ATP cadets at the end of August flushing out the pool yet again.