I can fully understand what you mean, and new players will definitely agree with you, but I want to add something to it. Your opinion states that new people should be able to get an airline started in the middle of all experienced ones. Thats nice, but wouldn't it be good for them to learn how the game works, get more experienced and get better at playing it. Me, for example have had to bankrupt so many times when I started. I picked the wrong aircraft, opened the wrong routes etc. But as time past by, I became more experienced, and by now I know how to play the game, which aircraft to order, and how to handle them correctly. I prefer games from which you need to learn, not the games when you'd easily win, without having to do anything, which, in my opinion, gets boring rather quickly. I bet Dantes or SAC didn't win immediately when they started playing (please correct me when I'm wrong), they had to learn too, to become the best nowadays!
A small note I want to add is that it is definitely possible to start halfway the game and still grow big. In the MT5 I started somewhere in 2009/10 and in the end of the gameworld I was among the biggest airlines in the Middle East.
P.S. I still have the opinion that the opening of another world halfway the existing one is good, and I agree with you notes about it.