Entry into airlines these days is relatively simple, borrow enough money and the job is yours. The 'chop' rate at civilian flying schools is non existent compared to military flying. Much of what is being covered in command courses now would have been covered previously as a part of continuation training for military pilots and through natural exposure within that all important first couple of thousand hours for those coming via the 'self improver' GA route and in both cases long before a civil jet command was due.
Companies have been all too eager to jump at the chance of a Pay2fly candidate, chuck him in the RHS and let the experienced captain deal with it, very different story when the company needs to strap a multi million pound jet to their backside and make them responsible for it. A present day command course could well be a CYA exercise by the company trying to make up for the lack of all the continuation training, either formally or through experience, that never happened.