Cadet programmes have been on for yonks and as far as I'm aware there is no correlation between them and aircraft crashing ... we don't want FAA 1500hr madness in Europe either so things are fine as they are fine as they are.
I think people are getting wrapped up in the premise of cadet only recruitment. BA have always recruited from a wide range of backgrounds and experience. I'm sure that will continue. This is not the first time Whitetail cadets have been taken on. I have several friends who joined BA from Oxford this way in the mid 2000s.
Regarding the '1500hr madness' imposed by the FAA; I'm not sure it's actually all that bad a thing. I flew for a couple of the US regionals for five years. The 1500hr rule was introduced just after I moved over there. In the space of just half a decade the average starting salary of a brand new FO at a regional has TRIPLED from $20,000 per year to $60,000 year. Additionally 'signing' bonuses of up to $25k are being offered as an incentive to join various carriers. In turn money on offer at the 'majors' has also increased exponentially. US pilots are now some of the best paid in the world.
Now I realise our significantly smaller demand for GA flying in Europe means that such a rule would never work here; but don't mistake the impact of the eagerness to get straight into the right hand seat of a jet at any cost as being anything other than detrimental to your future terms and conditions.
Everyone has to start somewhere, we're very lucky to have a great mixture of experience at BA. The opportunity to join will come up again. It's awful the way it has turned out for many this time, and for that you have my sympathy. Unfortunately with BA this isn't the first time and it won't be the last.