I agree it's a crappy way to treat applicants. Unfortunately for you, applicants aren't in short supply.
The problem is that the number of courses being run each year has been reduced considerably so assuming they kept the larger pool of trainees in the queue many of you would be waiting several more years for a course anyway.
With respect to age, there is no discrimination - you're judged against a standard which you either meet or don't. That said age is a disadvantage simply because the older you are the harder it is to keep up with the pace of the training.