Interesting subject.
In my humble point of view, 1500hrs although on paper may meet the requirements, is simply not enough to warrant a command position. Whether you are 25 or 55 does not matter, 1500 is the key figure. Of course with age you get life experience which is more than useful, however if you have the right outlook in life from the start and recieve the correct training, what is wrong with a youthful Captain?
In my last job we had a 23 year old chap as Capt on the ATR, he had been flying since his parents had first decided to ´have an early night´ and by word of mouth and experience was / is a very good pilot. Sure, for me at the start it was strange to see a younger guy than myself (me being 24 at the time) Captaining such a plane, but I soon realised why he was in that position.
For me as a recently qualified FO, at 1500hrs I will be nowhere near ready for a shot at Command, I know this and have never thought other wise nor would I want it. I am learning my trade, I make small mistakes, but over all I am pleased with the way things are going and have no illusions of grandeur.
I would like to think that I am doing a good job as an FO, but for me aged 25, Captaincy is a long way off, with much experience to be gained and things to learn on the way.
Its wrong to generalise, some people aged 25 are ready, some like myself are far from that, some will never be ready. Take each individual case on its own merits and if someone has acheived Captaincy at a young age on the basis of his / her ability and experience then credit to them
